Technical Reports 1-68 (1967-1973):

From 1967 until around 1993 WRRC published many reports on completed projects in-house. These “Technical Reports” contain a wealth of information on water issues, problems, and research, and are all available in PDF format at the University of Hawaii’s ScholarSpace institutional repository. Click on the report titles to go to the PDF.

SEARCH Technical Reports 1-68 (1967-1973): ARCHIVE

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Technical Report No. 1
TRAVEL OF ABS AND AMMONIA NITROGEN WITH PERCOLATING WATER THROUGH SATURATED OAHU SOILS

Reginald H. F. Young, L. Stephen Lau, Nathan C. Burbank
January 1967

ABSTRACT
A laboratory study was undertaken to determine the ability of four Oahu soils, Lolekaa, Lahaina, Manana, and Wahiawa, to remove ammonia, ABS, and coliforms from water percolating continuously through saturated soils. The soils utilized were chosen on the basis of their wide occurrence on the island in areas where percolating water may enter directly and in quantity into the ground water body that principally provides the island’s domestic water supply. All four soils had a high clay content and low pH. Laboratory tests were conducted with 10-ml burettes and subject to continuous saturated flow. Each contaminant was applied in solution one at a time to a fresh soil sample. Tap water was used for ABS and ammonia nitrogen while sewage was used to study coliform removal. All soils were effective in the removal of ammonia and ABS. One-hundred percent breakthrough for ammonia occurred after a throughput volume of 345 to 470 times the gross soil sample volume. For ABS it was 15 to 53 times the gross soil sample volume. The total exchange capacity for ammonia ranged from 29.3 to 50.1 micrograms of ammonia per gram of soil. The total adsorptive capacity for ABS ranged from 8.6 to 36.4 micro-grams of ABS per gram of soil. The applied concentration of ammonia was approximately 7.1 mg/l as found in a primary clarifier effluent and that of ABS was approximately 5.5 mg/l as found in a final clasrifier effluent. The results of coliform removal from percolating liquids were not conclusive because of small soil samples and the loading procedures. Preliminary tests verified some of the general principles developed elsewhere for effective coliform removal by ground disposal of sewage. The final clarifier effluent from a trickling filter was passed continuously through a 30″ column of Wahiawa soil and an initial coliform reduction of about 90% was effected.


Technical Report No. 2
INFILTRATION AND PERCOLATION OF SEWAGE THROUGH OAHU SOILS IN SIMULATED CESSPOOL LYSIMETERS

Melvin K. Koizumi, Nathan C. Burbank, and L. Stephen Lau
August 1966

ABSTRACT
This study investigated conditions contributing to cesspool failure and followed selected parameters to measure the degree of treatment afforded sewage in cesspool disposal. This laboratory study utilized bench scale soil lysimeters and two basic soil types: the Wahiawa Low Humic Latosol and the Lolekaa Humic Latosol. The soils were specimens from areas of potential urban development within known ground water recharge zones. The soils were molded into an “L” shape in the lysimeters to simulate the corner of a cesspool. The lateral soil column was 11 inches wide and the bottom soil layer was ten inches deep. A constant head of 11 inches was maintained in the pool of all for thirty to forty days. Pressures throughout the flow field were determined by piezometers and manometers. The side and bottom drains in the lysimeters allowed separate sampling and flow rate determinations. The Hawaiian soils exhibited typical die-away curves of infiltration with time depending on physical, chemical, and microbial qualities of both the feed and soil. Infiltration rates ranged between 0.7 to 3.6 ft/day. A 99% reduction of the infiltration rate was evidenced by the Wahiawa soil over the experiment-period of 30 to 40 days. Both sewage-fed lysimeters containing the Low Humic Latosol developed a pan-like layer of soil fines approximately 3 cm below the bottom of the cesspools, preventing the penetration of suspended solids after seven days. The Lolekaa soil did not show such changes. Flow nets plotted from pressure readings of the Wahiawa Low Humic Latosol showed that clogging occurred in the 8 to 10-cm zone of the side wall and the soil base of the lysimeters containing this soil. Flow through the lysometer was governed by infiltration, rather than percolation. Visual observation and negative manometer readings showed that unsaturated flow conditions were always present in all of the lysimeters throughout the experimental period. Both domestic and synthetic sewage fed exhibited a 90% reduction in organic nitrogen and a 62 to 96% reduction in COD. The oxidation reduction potential reading (-340 mv) indicated that anaerobic conditions existed within the cesspool: appreciable concentrations of nitrates in the effluent indicated that aerobic conditions existed in the soil mass surrounding the cesspool. The results of this experiment indicate that unless further degradation of the effluent is effected by the soil mass, the incomplete degradation of the sewage makes it a definite hazard to ground water sources. This study presents soil-effluent inter-reaction at a one-foot depth. No conclusive evidence exists to substantiate any further degradation of the effluent by the soil at greater depths to the required U.S. Drinking Water Standards of 45 mg/l of nitrates.


Technical Report No. 3
DYNAMIC AND STATIC STUDIES OF SEAWATER INTRUSION

L. Stephen Lau
February 1967

ABSTRACT
A theoretical equation was adapted and modified for a watertable aquifer to relate freshwater flow to the sea, geometry of the fresh water-sea water interface, and aquifer characteristics under dynamic equilibrium. Verification was obtained in laboratory experiments conducted in a hydraulic sand model. Other laboratory experiments revealed special flow patterns in the transitional zone of the freshwater-seawater interface. The extent and the vertical density gradient of the brackish water in the transitional zone were examined for their effects on modifying the conventional Ghyben-Herzberg ratio. Groundwater data collected from a deep well on Oahu, Hawaii was discussed as an illustration.


Technical Report No. 4
DEVELOPMENT OF DEEP MONITORING STATIONS IN THE PEARL HARBOR GROUND WATER AREA, OAHU

Doak C. Cox, and Chester Lao

March 1967

ABSTRACT
Two deep wells, one at Puuloa and the other at Ewa Beach in the Pearl Harbor area were drilled through the thick sedimentary cap into Koolau basalt, and have been readied for multiple-zone recording of water levels and water quality. Plastic pipes were lowered into the wells to selected depths determined by core composition and electric well logs. Gravel and beach sand were used selectively to backfill the wells. Thirteen sampling tubes were installed in the Puuloa well, and seven sampling points were placed in the main well at Ewa Beach. A shallow auxiliary well was also drilled at Ewa Beach. Evidence from preliminary development of the deep aquifer at Ewa Beach indicates the possible existence of a thin layer of fresher water floating on water of nearly seawater composition. Water levels are being monitored in this aquifer and show a tidal efficiency of approximately 15 per cent. The smaller sampling tubes are being developed at both sites.


Technical Report No. 5
A SURVEY OF LITERATURE ON GROUNDWATER RECHARGE AND SULFIDE GENERATION

James S. Kumagai
April 1967

ABSTRACT
A critical appraisal of the extant literature was made to evaluate the various studies and concepts derived from these studies pertinent to groundwater recharge with respect to treatment, transport, and storage of recharge water. The need for more scientific methods of underground disposal of waste waters, concepts of water filtration, mechanisms of clogging, and percolation studies is extensively reviewed. The extent of occurrence and optimum conditions for sulfide generation was also traced historically.


Technical Report No. 6
INSTRUMENTATION FOR SEISMIC EXPLORATION FOR GROUND WATER IN HAWAII

Leonard A. Palmer
April 1967

ABSTRACT
This study developed instrumentation and techniques to be used for seismic exploration of groundwater in Hawaii. A three-stage field test of instruments and methods was conducted to determine their capability of recording and reproducing seismic data. Reproducibility was the main criterion to permit using certain signal analysis techniques. Multichannel explosive tests utilizing dynamite shots were carried out in Waimanalo, Oahu during the first stage of testing. The second stage was the use of a two-channel magnetic tape recorder converted to receive voice and up-hole geophone signals on one channel and seismic signals on the other channel. Stage three tested the use of a “thumper” acoustical source, seismic filters and timers developed for the project. The signals generated by explosives and recorded photographically were very reproducible, but this is a relatively expensive method and analysis is slow. Seismic data recorded on magnetic tape allows versatility in analysis of recorded signals reproduced either in wiggle or intensity contrast analog form. Sections can be selected for digital computer analysis. The findings from this pilot phase of seismic exploration for groundwater does not indicate that seismology would not be an appropriate tool for studying geological structure. Success in further work will be implemented by this preliminary work in solving instrumentation and the number of personnel of the Water Resources Research Center and the Hawaii Institute of Geophysics who have been trained.


Technical Report No. 7
INFILTRATION AND PERCOLATION STUDIES OF SULFIDES AND SEWAGE CARBONACEOUS MATTER

James S. Kumagai
June 1967

ABSTRACT
The laboratory study of the infiltration and percolation of sulfides and sewage carbonaceous matter was conducted in two phases: Phase I utilized simulated cesspool lysimeters and Phase II considered the generation of sulfides and the infiltration and percolation of sulfides through soil and sand columns. Results from Phase I dictated a need for further study owing to free percolation of certain odorous compounds and excellent COD removals under presumably anaerobic conditions contrary to findings of similar studies in the literature. In Phase II the soil column was more effective for sulfide removal than the sand column which allowed continuous breakthrough of an odorous percolate. Organic removal indicated by TOC, COD, and BOD under anaerobic conditions was insignificant with BOD data indicating an increase in organic during percolation. The progressive movement of a black precipitate through the sand bed indicated that the filtering action of the sand was not as effective as the soil column. Under acid conditions, sulfide breakthrough was clearly demonstrated in both the sand and soil. The flow rate significantly improved in both columns after percolation of acidified fluids. AS columns exhibited the characteristic non-linear relationship between filtration and percolation rates and the hydraulic gradient. The results of the flow study can be described by the relationship of Hansbo (1960): V = ‘kin where V = velocity, i = hydraulic gradient, n constant describing permeability.


Technical Report No. 8
ELECTROMAGNETIC MAPPING OF HAWAIIAN LAVA TUBES

David von Seggern and William M. Adams
August 1967

ABSTRACT
A portable, electromagnetic loop-coupling device has been built to Locate points on the earth’s surface over points in an underground cavity and to determine the depth to the cavity. This method presently requires both an underground and a surface operator who each carry a motorcycle battery, a twenty-inch diameter loop antenna, and a compact transceiver circuit. The underground unit transmits to the surface a l200 hz signal which is essentially unattenuated and undistorted. The surface operator locates the transmitter by a nulling procedure. Three methods of determining depth are described. The accuracy of the location and the-depth determination with the loop-coupling device is checked with a transit survey. The device was applied with success to Kaumana Lava Tube on the island of Hawaii. Locations confirmed suspicions that the tube ran under roads and buildings. The roof of the tube was found to average about 25 feet thick. The accuracy of a compass-and-tape survey 4400 feet into the tube was checked by locations with the loop-coupling method and found to be in error by 20 feet. Lava tubes are significant as conduits of water and as geologic hazards.


Technical Report No. 9
BEHAVIOR OF SELECTED PESTICIDES WITH PERCOLATING WATER IN OAHU SOILS

Marshall A. Eto, Nathan C. Burbank, Jr., Howard W. Klemmer, and L.Stephen Lau
August 1967

ABSTRACT
This study investigated the ability of two Oahu soils, Wahiawa and Lahaina, to prevent chlorinated hydrocarbon pesticides; DDT and Lindane, in acetone solutions from percolating through the soils. The study was prompted by the possibility of contamination of Oahu’s domestic groundwater source by the two widely used insecticides. Wahiawa and Lahaina soils were effective in withholding DDT under saturated and intermittent flow conditions. Breakthrough of Lindane was noted in Wahiawa and Lahaina soil under saturated flow, and under intermittent flow conditions in Wahiawa soil only. Breakthrough concentrations were generally in the order of 0.3 ppm or lower. Breakthrough of Lindane and concentrations in the percolate were in direct proportion to soil volume. Column analysis showed that, in most cases, Lahaina soil held both pesticides in the upper three inches while Wahiawa soil held only DDT in the same region. Lindane was evenly distributed through the Wahiawa columns with a slightly greater count held at the surface. Pesticide loss through volatility in Lahaina soil was 60 to 80% of that noted in Wahiawa soil. Overall losses were as high as 50% for DDT and 25% for Lindane in the Wahiawa soil. Resistance to loss through volatility and retention of pesticides in soil appear to be directly related to organic matter content. Five Oahu soils tested to determine their ability to absorb pesticides from water-acetone solutions effectively removed pesticides in solute concentrations up to 1OO ppm. DDT and Lindane were removed in the order of 90 to 100% by swirling the soils in the pesticide solutions. No desorption occurred with water, but both pesticides were absorbed with benzene. Data obtained may be described by the Freundlich adsorption isotherm X/M = KC1/n where X/M = amount of pesticide sorbed per unit weight of soil, C = concentration of pesticide solution, and K = constant. values of K and n for Lindane sorption were in the range of 0.1 and 0.9, respectively, and for DDT they were in the order of 2.0 and 1.0, respectively.


Technical Report No. 10
FEASIBILITY OF RADIO SOUNDING TO THE GROUNDWATER TABLE IN HAWAII

George R. Jiracek
August 1967

ABSTRACT
The reported high values of resistivity in the near surface zones in semi-arid regions on the island of Hawaii motivated research into the feasibility of using radio waves to sound the depth to the ground water table. field tests using a 35 MHz ranging system (built in England for ice depth sounding) were made in areas of differing geology and climate, but in no instance was an echo identified as having originated from the water table. Measurements made of transmissions from within an inclined tunnel and received at the surface gave use to a signal which may have traveled through a water saturated rock column at a velocity of 27 m/usec while attenuated by about 3 db/m. Equipment ringing, due to antenna miss-matches, contributed to the lack of success in measuring water table echoes. However, subsequent laboratory dielectric measurements in the frequency range 102 to 6.2 x 107 Hz on representative Hawaiian rocks and soil indicate that even small counts of moisture result in prohibitive attenuation losses. For example, in a low density basset, the attenuation at 18 MHz is 0.26 CB/m when dry, but increases to 1.66 db/m with less than 4% water by volume. In a volcanic ash soil sample, the loss increases at 18 MHz from 0.04 db/m to 1.3 db/m as the soil water content is increased from zero to 19% by volume. Electromagnetic propagation velocities decrease markedly with increasing moisture content, an effect which is most striking at low frequencies. In situ moisture conditions above the water table in the semi-arid regions in Hawaii are expected to be approximately > 4% in rock and >19% in soil. Considering all factors, usable echoes at 35 MHz are consequently expected when sounding water table depths of ~ < 25 m. However, frequencies as high as 0.1 MHz may prove useful in sounding depths to many hundred meters. The use of VHF (30-300 MHz) waves to probe the depths of drier environments such as possibly exist on the moon is considered feasible.


Technical Report No. 11
SOME SEISMIC TECHNIQUES FOR MAPPING SMALL SCALE SHALLOW STRUCTURES

Cornelius Joziasse, William M. Adams
August 1967

ABSTRACT
Seismic recording and playback techniques and equipment arc being developed for use in mapping small scale geologic structures of significance in controlling the movement of ground water. High-frequency seismic waves produced by weight-dropping, or thumping, are used to provide the necessary resolution to detect these small structures. A vibrator has been constructed as another source of high frequency seismic energy. A D.C. motor is the transducer with storage batteries providing the power. A four-channel tape recorder is used to obtain seismic records on a 10-foot spacing. -This spacing gives good correlation from record to record. A storage oscilloscope gives visual displays of seismic data as wiggle line playbacks which are stored on the screen and then photographed. Also being used is variable intensity playback of reflection records. This allows signal averaging to be done optically and gives an easily interpreted display. A seismic survey done in the Waimanalo area on Oahu, Hawaii indicates that the thumper can produce sufficient counts of high frequency energy to permit shallow reflection prospecting.


Technical Report No. 12
BACTERIAL POLLUTION OF KANEOHE BAY, OAHU (June through August 1967)

K. R. Gundersen, and D. B. Stroupe*
December 1967

ABSTRACT
From June through August 1967, a thorough investigation was made of the presence and numbers of coliform bacteria, fecal streptococci (enterococci), and bacteria capable of growing on peptone-seawater agar at 28o. Six regularly monitored stations and several supplementary stations were established in the middle and southern sections of Kaneohe Bay. The latter receives considerably treated sewage effluent and some untreated sewage. In addition, analysis was made of sewage and sewage effluent from the Kaneohe municipal sewage plant, the Kaneohe Marine Corps Air Station (KMCAS) sewage plant, and Coconut island. Water from several small streams along the middle sector of the Bay was also tested. The fecal bacteria count was below the maximum set for Class AA water (according to the water quality standards proposed for the State of Hawaii) at all the regular stations on all occasions. The sewage treatment plants did not discharge any significant numbers of living microorganisms into the Bay; actually, the effluent from the Kaneohe municipal plant was found to be sterile after chlorination. The total count of bacteria in the Bay was generally high, but not alarmingly high. No correlation could be found between the bacterial count and the existing weather and tide conditions. In contrast to the low count of fecal bacteria in most parts of the Bay, rather high counts of coliforms, and especially enterococci, were found at several stations in shallow water in the middle sector. The sources of this contamination were found to be several of the small streams emptying into the Bay at this point. The streams from Kahaluu to Molii, as well as the shallow water of the Bay along the corresponding coastline, were also found to meet the proposed standards of Class II fresh water, however. In addition to the study of bacterial pollution of Kaneohe Bay, some data were collected from the sea south of the island of Maui and surrounding the island of Kauai.


Technical Report No. 13
PILOT EVAPOTRANSPIRATION STUDY: Lysimeter Design

Paul C. Ekern
August 1967

ABSTRACT
The marine sub-tropic climate of Hawaii is particularly suited to the use of semi-contained hydraulic lysimeters. Field experiences in the use of these lysimeters reveal a number of problems among which were factors related to the unusual tropical crops of pineapple and sugarcane. This project investigated the modification of the lysimeters to minimize some of these problems. Modular planting schemes in 1.52 meter rows or beds and tillage depths of 0.3 to 0.6 meters dictated minimal lysimeter size. The great height and lodging of the cane required a large lysimeter area to help in the definition of the effective transpiring area. polyester resin fiberglass reinforced tanks, 3 x 3 x 1.52 m deep with paper honeycomb strengthened bottoms were designed to meet the need for a large and relatively deep container of minimal weight. The prevalence of high relative humidities necessitated the use of engineering graph paper to reduce distortion of recording traces from shrinkage and swelling of the paper. Despite the limited diurnal and annual temperature variations, careful insulation of the exposed portions of the manometer was necessary. The regular diurnal changes in wind velocity imposed fluctuations on the open-end manometer used for recording the pressure changes in the hydraulic load cells that were offset by venting near ground level nylon reinforced butyl rubber irrigation hose with the ends clamped was used to form the bolsters for the load cells. A silicone rubber sealant was used to ensure water tight fittings with standard copper tubing connectors to the bolsters. Stability against rolling was achieved by placing some of the bolsters at right angles to the others. Large tensiometers of perforated polyvinyl pipe covered with porous Porvic membrane were designed to induce suction at the base of the soil column. The water release curves for the latosols suggested a 0.1 bar suction for an approximation of field capacity.


Technical Report No. 14
REMOVAL OF COLOR FROM THE WATER OF WAIKOLOA STREAM, SOUTH KOHALA DISTRICT, ISLAND OF HAWAII

Nathan C. Burbank, Jr., Po Lau Chan, Reginald H. F. Young
August 1967

ABSTRACT
The waters of the streams in the South Kohala district on the island of Hawaii have long been noted for their extreme high color and at times a distinct peaty taste. Early attempts to treat this water have led to the conclusion that the color bodies occurring in the water were refractive in nature and very difficult to remove except by an uneconomic chemical treatment. Investigation, over a one-year period, has found the colored bodies in the water of the Waikoloa Stream to be predominantly organic in origin with the color colloid having a negative charge. The color of the water varies from a maximum value of 320 units to a minimum value of 22 units. The average value is about 80 units. The zeta potential of the color colloid has varied from negative 36 mv to negative 18.5 mv. It was possible to remove color to the U. S. Public Health Service standards for interstate carriers by coagulating the color bodies with either alum or ferric sulfate. Coagulant aids can significantly reduce the quantity of the coagulant required to effect color removal. Coagulant aids decrease the required retention time in the flocculation basin and effects a faster rate of sedimentation. Further, color removal is generally improved. The most satisfactory coagulant aid is a cationic polymer, which not only acts as an aid but also as a true coagulant in color removal. Reductions by as much as 20 percent in the amount of primary coagulant required is possible while obtaining the same resists. The optimum pH range is 6 to 7 and the optimum dosage of cationic polymer is from 1 to 3 mg/l in conjunction with 15 to 20 mg/l of coagulant.


Technical Report No. 15
HYDROLOGICAL DATA AND PEAK DISCHARGE DETERMINATION OF SMALL HAWAIIAN WATERSHEDS: ISLAND OF OAHU

I-Pai Wu
HAES Technical Paper No. 939 – December 1967

ABSTRACT
Basic hydrological data including rainfall, runoff, historical flood, watershed characteristics, soil type, and land use of Hawaiian small watersheds on Oahu have been compiled and analyzed. Frequency analysis for annual peak discharge was made for 23 small watersheds on Oahu by using Gumbel’s extreme value theory. A regional flood formula has been derived for Honolulu and between mountain ranges of the island of Oahu through the use of multiple regression. The regional flood formula expressing peak discharge as a function of watershed area, length and height and a precipitation index defined as 100-year, 24 hour rainfall in inches can be used to estimate peak discharges for ungaged areas. The rational formula which is currently used for drainage areas less than 100 acres has been evaluated through the study of overland flow.


Technical Report No. 16
EFFECTS OF SOLUBLE ORGANICS ON FLOW THROUGH THIN CRACKS OF BASALTIC LAVA

Kenneth Ishizaki, Nathan C. Burbank, Jr., L. Stephen Lau
August 1967

ABSTRACT
The source of most of Oahu’s domestic water supply is from ground water occurring in the permeable materials of volcanic rock. Movement of the ground water is intrinsically through thin cracks in basaltic lava. This project studied passage of an organic-rich liquid through cracks in basalt. Permeability of “blue rock” portions of a basalt was determined as 2.6 x 10-4 gallons/day/ft2 of water, classing the rock as impervious. A range of 7.7 to 10.4 per cent in porosity values was obtained from the “Blue rock” portion; the clinker portion yielded a value of 50 per cent. Difficulties in experimental verification of the Hagen-Poiseuille’s derivation of radial flow through thin cracks were encountered in measuring flow at low gradients and aligning crack surfaces absolutely parallel. These discrepancies caused some variation in the determination. The flow rate is proportional to the 0.9 power of the head. Flow rates are less than theorized by Hagen-Poiseuille’s derivation with the flow rate of clarified sewage being less than tap water under identical conditions. The greatest retardation in flow of non-biodegradable liquids through thin cracks occurred in the initial hours followed by a systematic reduction of flow to a terminal and nearly constant flow of 718 to 1/100 of the initial flow rate. Flow rates through a basalt decrease faster than through a simulated thin crack made of lucite plastic. Flow of organic-rich liquids through such cracks, similar to non-biodegradable liquids, exhibits a decrease in flow initially and continues this trend for as long as 220 hours. The terminal flow velocity of tap water is much greater than that of sewage which appears to proceed to a no-flow condition. The clogging phenomenon was dependent upon microbial activity and food supply in sewage. Retardation of flow of organic-rich liquid is attributed to presence of microbial cells and their biochemically synthesized products in the cracks. The products are primarily polysaccharides and slimes along with ferrous sulfide, a common material found in septic sewage in contact with soil or rock.


Technical Report No. 17
ESTIMATION OF GROUND-WATER CONFIGURATION NEAR PAHALA, HAWAII USING ELECTRICAL RESISTIVITY TECHNIQUES

Donald M. Hussong, Doak C. Cox
August 1967

ABSTRACT
In 1965 the Water Resources Research Center of the University of Hawaii began development of the necessary equipment to explore the feasibility of an extensive resistivity exploration program. Subsequent funding permitted the organization of this project with the dual purpose of developing reliable and convenient instrumentation for resistivity surveying in the Hawaiian islands and to apply the technique toward the solution of a ground water problem in Pahala, on the island of Hawaii. A series of 14 electrical soundings was completed at Pahala in September 1966 in an attempt to determine the extent and causes of an anomalous high water table. Four of the soundings indicated the limits of this underground reservoir to be at least 3500 feet east and 2500 feet south of a Maui-type well shaft in Pahala. The southern extent of the high head ground water suggests the northeast-southwest trending of the eruptive fissure vent about 4000 feet southeast of the well as a likely hydrologic barrier. Other soundings, indicating intermediate level water tables along the direction of the strike of the vent toward Punaluu, suggest a series of similarly trending dikes forming steps of water entrapment dropping toward the ocean. To the north of the hypothetical sequence, a set of somewhat confused soundings indicate what may be ancient buried soil or ash surfaces serving as impermeable boundaries presenting direct normal ground-water flow from Pahala southwest above the dikes to the ocean south of Punaluu.


Technical Report No. 18
REMOTE SENSING OF HAWAIIAN COASTAL SPRINGS USING MULTISPECTRAL AND INFRARED TECHNIQUES

Larry K. Lepley, Leonard A. Palmer
August 1967

ABSTRACT
Two remote sensing techniques of measuring offshore ground-water spring discharge that have been studied are: (i) multispectral photography, and (ii) infrared thermometry. During the summer of 1967, exposure factors for filter-film camera combinations extending outside the visible spectra were experimentally determined and tabulated. One spectral series of simulated aerial photography was obtained. Darkroom procedures and equipment for multispectral enhancement of the suspected color differences between sea water and offshore spring water in these photographs have not yet been precisely defined. Helicopter flights with an infrared thermometer have demonstrated that offshore springs can be identified by their temperatures. Due to the irregular shape, size, and location of these fresh water outflows, a synoptic technique is needed. An infrared scanner is desirable but the present costs are prohibitive.


Technical Report No. 19
POTENTIAL WATER DEVELOPMENT OF THE KAHUA AREA, KOHALA, HAWAII

Chester Lao, William M. Adams
April 1968

ABSTRACT
On the basis of hydrology, geology, soils, and water quality, potential ground-water development along the coastal area of the Kahua area in the North Kohala District appears unfavorable for large supplies of fresh water. Low rainfall and the presence of barrier dikes limit recharge by percolation and underflow. Wells occurring near the coast are brackish and have low heads. A well in the wet uplands is essentially dry. South of the nearby town of Kawaihae ground-water sources of brackish quality are used for irrigation of a golf course and pasturage. Multiple low-yield wells parallel to the coast with maximize yield without further impairing water quality. Surface geophysical exploration and a study of upgrading the water quality economically for domestic use are suggested.


Technical Report No. 20
MIGRATION OF BACTERIOPHAGE T4 IN PERCOLATING WATER THROUGH SELECTED OAHU SOILS

Richard M. Tanimoto, Nathan C. Burbank, Jr., Reginald H. F. Young, L. Stephen Lau
June 1968

ABSTRACT
A laboratory study was made of the ability of three Oahu soils, Wahiawa, Lahaina, (both Low Humic Latosols), and Tantalus cinder (of the ashy cindery isothermic family of Typic Dystrandepts) to remove the caliphate T4 BrII mutant (a vegetative virus) from percolating waters. The soils were selected on the basis of their occurrence on the island of Oahu in areas where percolating water may enter directly and in quantity into the ground-water body that provides the principal portion of the island’s domestic water supply. on Oahu, 95 percent of the total agricultural product is cultivated in Low Humic Latosols. Two of the soils proved to be effective in retaining the T4BrII mutant virus but only at thicknesses greater than 2 1/2 inches. The Wahiawa and Lahaina soils were effective in the removal or adsorption of the coliphage T4 from percolating waters at the applied concentration of 2.5 x 106 per ml of feed solution through soil thicknesses of 6 inches and 2 1/2 inches. Adsorption at these thicknesses was 100 percent. Breakthrough of the viruses occurred in both Wahiawa and Lahaina soils at soil thickness of l 1/2 inches at applied concentration of 1.5 x 106 per ml of feed solution. The breakthrough began slowly, but increased rapidly with time and the rate of breakthrough varied with the soil. A higher rate was observed for Lahaina soil during the first two days of sampling. The Tantalus cinder proved ineffective in withholding the viruses at the applied concentration of 1.5 x 106 per ml of feed solution. Breakthrough of concentrations of 105 of the phage (plaques) were recorded through soil thicknesses of 15, 12, and 6 inches.


Technical Report No. 21
APPLICATION OF ELECTRIC WELL LOGGING AND OTHER WELL LOGGING METHODS IN HAWAII

Chester Lao, Frank L. Peterson, Doak C. Cox
November 1969

ABSTRACT
In 1966, the Water Resources Research Center initiated a comprehensive study of electric well logging and other geophysical well logging techniques in Hawaii. The primary objectives of this study were to determine what results could be obtained by the use of conventional electric and geophysics well-logging methods under Hawaiian conditions and to collect as much basic geologic, hydrologic, and geometric information as possible from wells in Hawaiian aquifers. The functions logged include spontaneous potential, point resistivity, short and normal resistivity, lateral resistivity, water temperature, water conductivity, and caliper. Resistivity logging in Hawaii produced much important qualitative information and some quantitative information. Resistivity logs from wells in basaltic aquifers indicate the location, number, thickness, and total thicknesses of permeable and less permeable formations and are extremely useful as indicators of water-yielding zones. High resistivities generally are indicative of dense impermeable basalts and low resistivities are indicative of porous permeable zones most likely to contribute water to the borehole. The logs also provide a direct measurement of depth to water, depth of casing, and depth of hole. Spontaneous potential logs sometimes are inconsistent and unreliable and are used primarily for correlation with other logs. Conductivity and temperature logs provide a direct quantitative measure of water conductivity and water temperature and provide considerable insight into the depth, thickness, quality, and temperature of waters contained in the wells of Hawaii. Borehole conductivity and temperature data also aid in the interpretation of the complex dynamic Ghyben-Herzberg lens relationships. The caliper module, which provides a measure, of the well diameter, has been subject to frequent mechanical breakdown, however, recent alterations of the caliper module’s design should allow the device to perform to its expected capability. Borehole photography employed recently by the Board of Water Supply provides positive identification of most Hawaiian rock types. Observation between the photologs and electric logs is very good.


Technical Report No. 22
TRITIUM MEASUREMENTS IN NATURAL HAWAIIAN WATERS: INSTRUMENTATION

L. Stephen Lau, Tsegaye Hailu
November 1968

ABSTRACT
All known tritium measurements made of Hawaii rainwater, ocean water, surface water, and ground water are summarized. Ocean water yielded 10 to 20 T.U.. in 1963-65. Tritium in rainwater rose from a low 6 T.U.. in 1961 to a 1963 summer peak of 373 T.U.., exhibited strong seasonal fluctuations, and declined to 43 T.U.. in mid-1965. Groundwater samples collected in late 1966 on Oahu ranged between 24 to 0.5 T.U.. Ground-water samples with high tritium count were taken from high-level water; those with considerably less tritium were basal water and the one with the least tritium was basal water farthest down gradient and below a 1100-foot caprock in Ewa Beach, Oahu. The facilities of the Tritium Laboratory at the University of Hawaii are described. The present basic unit for tritium analysis utilizes liquid scintillation with electrolysis for enrichment of low-level samples.


Technical Report No. 23
AN ELECTRICAL RESISTIVITY PROFILE FROM MAHUKONA TO KAWAIHAE, HAWAII

William M. Adams
HIG Series, HIG-WRRC – I – November 1968

ABSTRACT
In order to locate the restively optimum sites for drilling exploratory holes for fresh water, an electrical resistivity survey was conducted among the new Mahukona-Kawaihae Road on the west flank of the Kohala Mountain. Two resistivity soundings were run using the Schlumberger spread configuration to determine a satisfactory spacing for a Wenner profile spread. Using an “a” spacing of 275 feet, a profile of 209 stations was run using the Wenner spread configuration. The data were correlated with elevation at 0.41, so a procedure for removing the elevation effect from observed apparent resistivity was developed. The procedure is probably uniquely applicable to insure environments. Based on the reduced resistivity profile, four relatively optimum sites for additional exploration, such as by drilling, are specified. There is not, however, any interpretation of the data that can definitely indicate the occurrence anywhere on the profile of age underground reservoirs of fresh water. This is because the interpretation-of profile data is essentially relative, not absolute.


Technical Report No. 24
COASTAL EVIDENCES OF GROUND WATER CONDITIONS IN THE VICINITY OF ANAEHOOMALU AND LALAMILO, SOUTH KOHALA, HAWAII

Doak C. Cox, Frank L. Peterson, William M. Adams, Chester Lao, John F. Campbell, Richie D. Huber
March 1969

ABSTRACT
The rocks at the surface in Anaehoomalu and Lalamilo primarily are lavas from Mauna Loa which flowed through the saddle between Mauna Kea and Hualalai. These basalt lava flows, partly pahoehoe, but mainly aa, are generally quite permeable. No perched water or dike-impounded water is known in the area, certainly not close to the shore, and the fresh ground water is believed to occur in a thin layer at about sea level. Ground-water flux through the Anaehoomalu and Lalamilo districts is thought to be quite low, owing to the small recharge which results from the generally low rainfall and the high evapotranspiration. Computations of recharge from annual rainfalls and losses from evapotranspiration suggest that the discharge along the shoreline averages only a few million gallons per day per mile.
Onshore reconnaissance, which included sampling and electrical resistivity, and an offshore conductivity survey confirm that fresh and brackish water appears to be discharging along the coastline from Hapuna Bay to Keawaiki Bay in quantities too small to be easily detected. No anomalously high ground-water levels which might indicate the presence of large ground-water flows were detected.

A preliminary survey of salinity of coastal wells, springs, and water holes, and a visual search for ground water discharging at the shoreline did not show any evidence of such discharges on the order of millions of gallons per day. These data prompted an offshore salinity survey and electrical resistivity profiling onshore.

The offshore reconnaissance did not detect distinctly fresh water. However, ten areas of discharge of brackish or fresh water were detected. Although it is extremely difficult to determine the exact volume of discharge, a reasonable estimate of the volume of flow of brackish and fresh-water discharges ranges from a few tens of thousands of gallons per day at eight discharge points to perhaps one million gallons per day from each of the two larger discharge zones. No evidence indicates that the flow of brackish and fresh water from the ten discharge points detected by this survey exceeds a few million gallons per day.

All of the brackish and fresh-water discharges were detected in bays. It is not known whether this represents the true pattern of discharge or whether water being discharged along headland areas is very rapidly dissipated because of the high concentration of surf energy.

Electrical resistivity profiles using a Wenner spread were taken at 185 locations and electrical resistivity soundness, using a Schlumberger spread, were made at three of these, location. The soundings showed ground water to be very conductive up to sea level, and also indicated that the 70-foot spacing between sounding sites was appropriate for the profiling. Neither a depression in the fresh-saline interface nor a higher permeability region having fresher water was indicated in the profile. Since profiling data are relative, interpretation is rather simple. By the combined use of sounding and profiling data, a layer of brackish water eight feet thick, equivalent to a head of two-tenths of a foot, should have been discernible, but no detectable fresh-water body of any thickness was found.


Technical Report No. 25
REFLECTIVITY OF ELECTROMAGNETIC WAVES AT AN AIR-WATER INTERFACE FOR PURE AND SEA WATER

Larry K. Lepley, William M. Adams
December 1968

ABSTRACT
Compilation of the optical properties of electromagnetic waves incident on pure (chemically pure) or sea water shows an abrupt divergence of behavior for the two water types at about the 3-centimeter wavelength. From this point on to all longer (ratio) wavelengths, sea water behaves optically like a metal, whereas pure water behaves like a semiconductor. At shorter wavelengths (below 3 centimeters), both fresh and pure water behave as dielectrics with similar optical properties. Only at visible wavelengths are the optics of natural waters of all salinities well known. The reflectivity contrast (difference in reflectivity divided by average reflectivity) between pure and sea water to visible light is approximately 3%. The reflectivity contrast between sea and pure water at radio frequencies is approximately 44%.


Technical Report No. 26
INFRARED IMAGES OF THE KAU AND PUNA COASTLINES ON HAWAII

William M. Adams, Larry K. Lepley
– HIG Series, HIG-WRRC – 2 This is a report of cooperative research published with the approval of the Director of Water Resources Research Center and the Director of the Hawaii Institute of Geophysics,

December 1968

ABSTRACT
An infrared scanner covering the 200 to 540-nanometer wavelength region has been flown over the coastline of the Puna and Kau Districts on the island of Hawaii. The images were monitored in real-time and recorded on film. Only a 5o x 5o lens (narrow-angle) was available, hence the flight line had to be at an altitude of 11, 000 feet in order to make each image about 1000 feet on a side. The films of the images have been processed and catalogued. A few areas have been mossaiced to facilitate interpretation. This report briefly describes the equipment used, the field procedures followed, and presents an index to the catalogued films. A few frames and mosaics are presented to illustrate the image quality. The procedure in its entirety is rather complex and much practice is necessary to obtain high quality images. The greatest difficulty seems to be due to the high-level flight line demanded by the narrow angle tens. Future surveys will use wide angle Lens, such as has just become available.


Technical Report No. 27
ANAEROBIC DIGESTION OF PINEAPPLE MILL WASTES

Martin J.K. McMorrow, Reginald H.F. Young, Nathan C. Burbank, Jr., L.Stephen Lau, Howard W. Klemmer

Center for Engineering Research

ABSTRACT
To determine the response of pineapple mill waste to anaerobic digestion, a simulated mill waste with a COD value equal to actual mill waste was made from commercial pineapple juice for this study. Aluminum hydroxide was used as a pH control and a nitrogen supplement. The study utilized batch-anaerobic digesters in initial stages to find optimum conditions for long-term studies which were conducted in 9-liter bottles with periodic removal of digested waste and addition of fresh waste. Seed was composed of digested domestic sewage sludge, bottom sediment from a canal used for disposal of pineapple mill waste, and fermented pineapples and pineapple juice. Principal studies involved three digesters maintained at ambient temperature as controls two digesters with 75 mg/l of phosphorus added, two digesters heated to 90oF, and one digester whose contents were mixed by recirculation of digester gases. The digesters were operated for sixty days. Analytical parameters were COD, sugar, pH, ORP, volatile acids, gas production, gas composition, alkalinity, and total bacteria by the Breed Counting Method. The results of the study showed that pineapple mill waste undergoes a rapid initial decomposition. A reduction in COD occurred along with a rapid drop in sugar concentration and subsequent formation of volatile acids. Following initial activity, there is a period of inactivity after which recovery from the acid stage occurs and a steady reduction of waste material begins. The test data collected indicated that raw pineapple waste liquor is unsuitable for anaerobic digestion unless it is heated, stirred, or treated with phosphate. After sixty days of operation, digesters at ambient temperature, and those with added phosphorus, and those that were stirred produced a COD reduction of 40, 51, and 53 percent, respectively. There was strong evidence that pineapple mill waste may be satisfactorily treated anaerobically if it is heated and optimum conditions exist. Digesters operated at 90oF effected 66 percent reduction in COD with a steady production of gas containing at least 75% CH4.


Technical Report No. 28
AEROMAGNETIC, GRAVITY, AND ELECTRICAL RESISTIVITY EXPLORATION BETWEEN PAHALA AND PUNALUU, HAWAII

William M. Adams, Surendra P. Mathur, Richie D. Huber – February 1970

ABSTRACT
Aeromagnetic, electrical resistivity, and gravity surveys were conducted in the area between Pahala and Punaluu, Hawaii to delineate barriers to ground-water movement. The geophysical data are interpreted and compared to determine the sectors of relatively low gradient ground water between the barriers. In the Pahala area, two barriers to lateral ground-water movement have been located: the Kolea barrier, which trends roughly east to west, and the second barrier, associated with a “crack” used as the Pahala dump, designated by this study as the Pahala dump barrier. The Pahala dump barrier definitely appears to terminate at the Kolea barrier. These barriers are defined by magnetic, gravity, and electrical sounding and profiling observations. In the Punaluu area, electrical sounding and profiling observations agree with the conclusions of an earlier infra-red study that a large fresh-water outflow, associated with a relatively high head of the water table, occurs. Magnetic and gravity observations agree on the presence of a skewed prismatic body with the top of the body being close to the ground surface. Two test holes have been drilled in the area. The findings verify the geophysical predictions.


Technical Report No. 29
SILICA IN STREAMS AND GROUND WATER OF HAWAII

Stanley N. Davis
January 1969

ABSTRACT
Concentrations of silica in natural waters of Hawaii vary from less than 0. 2 ppm in rain water to almost 90 ppm in ground water. The acquisition of silica by the water is probably most rapid near the ground surface. Between 1 and 3 ppm will go into solution within a few minutes after rain comes in contact with the rock and soil. Rain water that percolates to the subsurface and eventually becomes groundwater recharge will have from 5 to 20 ppm silica before it reaches high-level dike compartments. The high-level water will continue to dissolve more silica until it has from 15 to 45 ppm silica. Some of the dike water will discharge into streamss which in turn recharge the basal-water body and some will leak directly into the basal-water body. Basal water that may start with 25 to 45 ppm silica will slowly dissolve more silica until it contains from 30 to 60 ppm. Concentrations of more than about 40 ppm appear to be correlated with irrigation return water and in addition may be owing to dissolution of less weathered rocks in the more arid parts of Oahu as well as the other islands of Hawaii. Rates of silica removal in small watersheds of the high-rainfall portions of the Koolau Range appear to be as much as 8 mg/cm2/yr, which is more than any other area in the United States. silica in a relatively soluble form in the basaltic bedrock together with unusually large amounts of water from frequent rains account for the rapid removal of silica in solution. Warm climate and tropical vegetation do not appear to be necessary for the rapid leaching of silica.


Technical Report No. 30
Hydrograph study and peak discharge determination of Hawaiian small watersheds: Island of Oahu.

I-Pai Wu
March 1969

ABSTRACT
Hawaiian small watersheds are unique in watershed hydrology because of the high infiltration rate, small size, and mountainous topography. The flood hydrograph which has a short time to peak and small recession constant can be expressed as a steep triangular shape. A peak discharge equation is derived from the concept of a triangular hydrograph and a linear storage of recession flow. The peak discharge equation can be shown as a very simple form, Qp = CAR, where C is a coefficient and can be determined by the hydrograph time parameters, time to peak and recession constant, A is the watershed area, and R is surface runoff in inches. A linearity test between peak discharge and runoff has been made for Hawaiian small watersheds and a good linear relationship was found between peak discharge and surface runoff which is less than six inches not only for an individual small watershed but for watersheds of similar size.


Technical Report No. 31
ESTUARINE POLLUTION IN THE STATE OF HAWAII

Doak C. Cox and Lawrence C, Gordon Jr. VOL.1 STATE WIDE STUDY MARCH 1970

PREFACE
This report is the result of a one-year study of pollution of estuaries in the State of Hawaii undertaken by the University of Hawaii for the Federal Water Pollution Control Administration under contract no. 14-12-446. Estuarine pollution is both a local and a national concern. Among faculty members of the University of Hawaii concerns with the ecological effects of pollution in estuaries in general, and Kaneohe Bay on Oahu in particular, had been mounting for some time. There were also concerns with the growing problems of waste disposal and with the physical, biological, and economic implications of recently adopted Water Quality Standards. At the national level, the Federal Water Pollution Control Administration was authorized and instructed under the Clean Water Restoration Act of 1966 to undertake a National Estuarine Pollution Study. The study reported here grew out of initial correspondence begun in 1967, and particularly discussions held in December of that year, between interested faculty members and representatives of the FWPCA. Field work was initiated early in June 1968 with the interim support of the University’s Office of Research Administration and expanded rapidly following the approval of the contract by 29 June 1968. A progress report was submitted to FWPCA in December 1968 (Water Resources Research Center Memorandum Report No. 15). Field work was terminated 30 June 1969, when a first draft of this report was transmitted to the FWPCA. The study included two major projects, a statewide review of estuaries and their pollution based on already existing information, Vol. 1 of this report, and a special study of ecological factors and pollution in Kaneohe Bay, Vol. 2 of this report. It involved faculty from several units of the University and administrative assistance of the Hawaii Institute of Marine Biology and the Agricultural Economics Department as well as that of the Water Resources Research Center.


Technical Report No. 31a
ESTUARINE POLLUTION IN THE STATE OF HAWAII

– VOL.2 KANEOHE BAY STUDY NOVEMBER 1973


Technical Report No. 32
A HYDROGEOPHYSICAL SURVEY FROM KAWAIHAE TO KAILUA-KONA, HAWAII

William M. Adams, Frank L. Peterson, Surendra P. Mathur, Larry K. Lepley, Clifton Warren, Richie D. Huber
HIG Series, HIG-WRRC – 4 This is a report of cooperative research published with the approval of the Director of Water Resources Research Center and the Director of the Hawaii Institute of Geophysics. – September 1969

ABSTRACT
Several geophysical surveys have been conducted over the coastline area between Kawaihae and Kailua-Kona for the purpose of locating the optimum sites for possible development of ground water from the basal lens. A low-level aeromagnetic survey over the area and an infrared scanning effort along the coast with surface verification provided general reconnaissance information. Audiomagnetotelluric and D. C. electrical resistivity profiles defined more detailed, local structures. The infrared scanning survey along the coastline did not reveal any thermal anomalies that are reasonably attributable to previously unknown outflows of brackish water of magnitudes adequate for currently anticipated commercial exploitation. However, the aeromagnetic and audiomagnetotelluric surveys locate four lines which are possible barriers to lateral movement of basal ground water. Due to recharge considerations, only two areas were identified for test drilling, and these lie at elevations of more than 1, 200 feet. The D. C. electrical resistivity profiling was conducted at an elevation of about 100 feet or less. Based on the resistivity data, three possible sites for test drilling are selected — two are in the north near Puako Bay and the other is above the present Kona Airport. The anomaly suggesting this latter site has probably been adequately tested by the test well already completed mauka of the site.


Technical Report No. 33
IDENTIFICATION OF RETURN IRRIGATION WATER IN THE SUBSURFACE: WATER QUALITY

Pedro A. Tenorio, Reginald H. F. Young, H. Collins Whitehead
October 1969

ABSTRACT
A joint research effort was undertaken by the Water Resources Research Center and the Honolulu Board of Water Supply to investigate the physical and chemical characteristics of irrigation return water in Pearl Harbor-Waipahu, Oahu, which is an area used for tropical agriculture. The project was started in 1967 and was expanded in 1968 to include Kahuku, Oahu and Central and West Maui. Well samples and profile samples were obtained with a thief sampler in the Pearl Harbor-Waipahu area and composite samples were obtained mainly from pumping wells in other areas. In addition, both spring and stream waters in the Pearl Harbor-Waipahu area were analyzed for a number of inorganic constituents including bicarbonate, calcium, magnesium, phosphate, silica, boron, chloride, nitrate, sodium, potassium, bromide, fluoride, iodine, sulfate, and total hardness. Stream waters in the main study area were observed to contain appreciable quantities of nitrate, phosphate, bromide, bicarbonate, and fluoride. Similar trends were observed with the spring samples including increases of calcium, magnesium, silica, sulfate, and nitrate. Waters from Waiau and Waiawa Springs were found to be closer to sea water in cation composition than that from Kalauao Springs. Well waters from the main study area were evaluated according to Visher and Mink’s index constituents, silica, sulfate, and nitrate, and other significant ionic compositions. Well T-241 generally showed higher content of index ions compared to basal water indicating the possibility of its penetrating a caprock aquifer. The waters of T-75 gave evidence of its being in the transition zone between sea water and basal water. T-52 was thought to be in “virgin” basal water. Wells T-202-2C and T-118 are in pumping well fields and show evidence of some freshening due to the draft for municipal use. Well T-191-3A and T-191-3B yielded an erratic pattern that was difficult to analyze, complicated by the fact that the two shafts are about 100 ft apart. General analysis of major constituents evidenced a cyclical trend in concentration, either related to seasonal rainfall and irrigation practices, or both.


Technical Report No. 34
SOME MEASUREMENTS OF THE TRITIUM CONTENT IN THE NATURAL WATERS OF SOUTHERN OAHU, HAWAII

Theodorus H. Hufen, Robert A. Duce, L. Stephen Lau
November 1969

ABSTRACT
An analysis was made of the tritium content of samples from various sources of surface and subsurface waters of the island of Oahu. Twenty rainwater samples collected from various rain gages located on the Koolau Range over a period of four months showed an activity between 16.3 and 28.2 tritium units. Samples from four streams in the Pearl Harbor area ranged from 14.5 to 21.3 tritium units, while samples from two springs and five wells in this same area all showed an activity below 5 tritium units. The instrumentation consisted of an electrolysis enrichment apparatus, a vacuum distillation unit and a liquid scintillation counter. A detailed description is given of the various parts of the electrolysis apparatus and the vacuum distillation unit. Both the enrichment and counting procedures are reviewed as well as the calibration of these systems.


Technical Report No. 35
EFFECTS OF SURFACE RUNOFF AND WASTE DISCHARGE INTO THE SOUTHERN SECTOR OF KANEOHE BAY: JANUARY – APRIL 1968

Edison L. Quan, Reginald H. F. Young, Nathan C. Burbank, Jr., L. Stephen Lau
January 1970

ABSTRACT
A study of the surface water quality in the southeastern portion of Kaneohe Bay was undertaken between February and mid-April, 1968. The aims of this project were to determine: (1) the effect of surface runoff on water quality in the Bay, (2) the chemical and bacterial content of wastewaters emerging from two sewage treatment plant outfalls, and (3) whether the overall water quality standards were met. High rainfall and subsequent high surface runoff introduce high concentrations of nitrate-nitrogen and fecal streptococci into the lower reaches of Keaahala and Kaneohe streams. High concentrations of fecal streptococci also occur in waters overlying a clam bed during high stream flows, suggesting that a potential public health hazard may exist during the rainy period. High land runoff lowers the water temperature by 2oC, over dry weather flow and causes silt turbidity along the nearshore waters in the Bay. Phosphate-phosphorus concentrations in the Bay waters at the location of waste discharge averaged 0.046 mg/l for the Kaneohe sewage treatment plant and 0.033 mg/l for the Kaneohe Marine Corps Air Station sewage treatment plant, exceeding the limit established for Class A waters by 0.021 and 0.008 mg/l, respectively. Surface runoff is not a significant contributor of phosphates into the Bay compared to the sewage waste discharge. In general, the dissolved oxygen content and pH adequately met the water quality standards at all stations except for two low dissolved oxygen readings in Keaahala Stream. From mid-bay to the northern portion of the Bay, the parameters utilized indicated that the overall water quality met the standards established for both Class AA and A waters.


Technical Report No. 36
MIGRATION OF POLIOVIRUS TYPE 2 IN PERCOLATING WATER THROUGH SELECTED OAHU SOILS

Daniel H. Hori, Nathan C. Burbank, Jr., Reginald H., F. Young, L. Stephen Lau, and Howard W. Klemmer
January 1970

ABSTRACT
A laboratory study was made to determine the ability of three Oahu soils, Wahiawa, Lahaina, (both Low Humic Latosols), and Tantalus cinder to prevent possible contamination of the basal water lens by the passage of virus. The study was performed utilizing columns containing the selected soils and subject to intermittent percolating water containing a known concentration of Poliovirus Type 2, simulating the action of a cesspool leaching into the ground. The effluent from the soil column was collected and analyzed for viral content by the plaque forming techniques. Breakthrough of the virus occurred in both Wahiawa and Lahaina soils at soil thicknesses of 6-inch, 2 1/2-inch, and 1 1/2-inch at applied concentration of 1.5 x 105 pfu/ml of feed solution. The virus removal was over 97 percent of the applied titer. The Tantalus cinder proved ineffective in withholding the virus at the applied concentration of 1.5 x 105 pfu/ml of feed solution. The virus breakthrough varies between 39 percent to 78 percent of the applied titer.


Technical Report No. 37
CONSUMPTIVE USE OF WATER BY SUGARCANE IN HAWAII

Paul C. Ekern
July 1970

ABSTRACT
Water use by sprinkler irrigated sugarcane under flat-bed culture was measured in four 100 ft2 by 5 ft deep hydraulically weighed lysimeters at the Kunia substation of the Hawaiian Sugar Planters’ Association. Nine-week-old one-eye cane transplants were set into a 5-foot grid in Molokai Low Humic Latosol on 27 October, 1968. Water use approached a 1:1 ratio with a conventional class A pan by late March, 1969 for a 3.5 leaf area index. Average values were 0.25 in/day for the midsummer months. The cane was ratooned on 10 May, 1969 and water use was reduced to a 0.33 fraction of pan evaporation. The cane regrew rapidly and water use was again equivalent to pan evaporation by July, 1969. Neither gypsum resistance blocks nor the neutron probe gave acceptable measurements of water withdrawal from Molokai Low Humic Latosol. Clear day net radiation over the canopy with a mid-day reflectance of 0.21 was: net radiation = (1- reflectance) sunlight -0.15 ly/min. Consumptive use by cane or pan often equaled or exceeded the net radiation, indicating strong positive advection of heat from the surroundings. During the early stages of cane growth, percolate from heavy winter rains contained as great as 225 ppm nitrate, but as the cane matured, the percolate had less than 1 ppm nitrate though the content of other solutes such as chloride, sulfate, and silica remained high.


Technical Report No. 38
REMOVAL OF COLOR FROM THE WATER OF WAIKOLOA STREAM, SOUTH KOHALA DISTRICT, ISLAND OF HAWAII

Nathan C. Burbank, Jr., Po Lau Chan, Reginald H. F. Young
March 1970

ABSTRACT
The waters of the streams in the South Kohala District on the island of Hawaii have long been noted for their extreme high color and at times a distinct peaty taste. Early attempts to treat this water have led to the conclusion that the color bodies occurring in the water were refractive in nature and very difficult to remove except by an uneconomic chemical treatment. Investigation, over a one-year period, has found the colored bodies in the water of the Waikoloa Stream to be predominantly organic in origin with the color colloid having a negative charge. The color of the water varies from a maximum value of 320 units to a minimum value of 22 units. The average value is about 80 units. The zeta potential of the color colloid has varied from negative 36 mv to negative 18.5 mv. It was possible to remove color to the U. S. Public Health Service standards for interstate carriers by coagulating the color bodies with either alum or ferric sulfate. Coagulant aids can significantly reduce the quantity of the coagulant required to effect color removal. Coagulant aids decrease the required retention time in the flocculation basin and effects a faster rate of sedimentation. Further, color removal is generally improved. The most satisfactory coagulant aid is a cationic polymer, which not only acts as an aid but also as a true coagulant in color removal. Reductions by as much as 20 percent in the amount of primary coagulant required is possible while obtaining the same resists. The optimum pH range is 6 to 7 and the optimum dosage of cationic polymer is from 1 to 3 mg/l in conjunction with 15 to 20 mg/l of coagulant.


Technical Report No. 39
MODEL STUDIES OF TIDAL EFFECTS ON GROUND WATER HYDRAULICS

John A. Williams, Ronald N. Wada, Ru-yih Wang
May 1970

ABSTRACT
This report presents the results of a model study on the propagation of periodic fluctuations in the piezometric head through a saturated porous media. Three different models were employed: a hydraulic model, a mathematical model, and an electrical analog model. The hydraulic model consisted of one or more layers of polyurethene foam placed in a lucite tank. The foam was tested in a confined and unconfined condition using both a no-flow and a constant-head boundary condition at the internal boundary. The mathematical and electric analog models duplicated the conditions in the hydraulic model. The results of the study indicate that diffusion theory can describe the propagation of such disturbances provided that the boundary conditions are satisfied and that the correct diffusion coefficient is employed. The calculation of the correct diffusion coefficient requires that an appropriate storage coefficient and an apparent porosity be used for the confined and unconfined models, respectively. For the unconfined case, the ratio of the apparent porosity to the true porosity is of the same order of magnitude for both the polyurethene foam and a Sacramento River sand.


Technical Report No. 40
RELATIVE TOXICITIES OF SELECTED CHEMICALS TO SEVERAL SPECIES OF TROPICAL FISH

Jerry H. Nunogawa, Nathan C. Burbank, Jr., Reginald H. F. Young, L. Stephen Lau
August 1970

ABSTRACT
This study determined the 24, 48, 96-hour median tolerance limit of phenol, DDT., dieldrin, and lindane of five species of fish commonly found in streams and estuaries in semi-tropical areas. They are: (i)Gambusia affinis – mosquito fish., (ii) Lebistes reticulatus- guppies, Tilapia mossambica – tilapia., (iv) Kuhlia sandvicensis – aholehole, and (v)Stolephorus purpureus – nehu. Of the five species, Gambusia affinis had the highest tolerance to the toxic agents used in this study. Lebistes reticulatus and Tilapia mossambica had approximately the same sensitivity to DDT as well as dieldrin and lindane. Lebistes reticulatus had a higher sensitivity to phenol than Tilapia mossambica. Although Stolephorus purpureus, nehu, was highly sensitive, Kuhlia sandvicensis was most sensitive to all toxic agents used.


Technical Report No. 41
ELECTRODIALYSIS FOR DESALTING HAWAIIAN BRACKISH GROUND WATER: A FIELD STUDY

L. Stephen Lau, James C.S. Chou
July 1970

ABSTRACT
A field study was made to evaluate the applicability and problems of desalting brackish ground water from basaltic and reef limestone aquifers in Honolulu, Hawaii with the electrodialysis process. The three-week study indicated that the brackish water at both sites was upgraded to potable quality and the rejection of ionized salts was above 80 percent. No pretreatment was necessary. Both the average production and rejection rates were about 420 gpd. An economic evaluation was not determinable from the short-term results.


Technical Report No. 42
INSTANTANEOUS UNIT HYDROGRAPH ANALYSIS OF HAWAIIAN SMALL WATERSHEDS

Ru-Yih Wang, I-Pai Wu, L. Stephen Lau
HAES Journal Series No. 1259 August 1970

ABSTRACT
The analysis of about 240 flood hydrographs of 29 small watersheds on the island of Oahu, Hawaii, shows some unique hydrologic characteristics. A typical Hawaiian small watershed has a small area, flash peak, short time to peak, and small recession constant. Most of the hydrographs have the typical shape of a steep triangle. Based on statistical analysis of the observed flood hydrographs, a linear relationship has been found between peak discharge and the volume of runoff for each watershed. Because of the similar shape of the semi-dimensionless hydrographs, a unit-hydrograph with uncertain duration can be developed for each small watershed. The duration of such unit hydrographs can be determined by using the S-hydrograph technique with the equilibrium discharge as a criterion and the trial-and-error method utilizing & digital computer. The durations of the unit hydrograph, or the effective rainfall durations for Hawaiian small watersheds, were found to range from 5 minutes to one hour. A good correlation has been found to exist between effective rainfall duration and the watershed area. Such a short duration unit hydrograph can be used to develop an instantaneous unit hydrograph by using Nash’s conceptual model and the method of moments, assuming the effective rainfall is uniformly distributed with respect to time and space. The instantaneous unit hydrograph for each watershed can then be solved by a computer. The two instantaneous unit hydrograph parameters, Gamma function argument, N, and reservoir storage constant, K, were found to correlate with areas of small watersheds. The instantaneous unit hydrograph of a given ungaged area can be determined by knowing the area of the watershed. The flood hydrograph with a given duration can also be solved by applying the incomplete Gamma function. The superposition characteristics of a Linear model can be applied for hydrograph analysis of Hawaiian small watersheds. Hence, the design discharge with certain recurrence years for different engineering purposes can be directly multiplied with the design runoff, which may be obtained with the reference of the rainfall depth-frequency-duration charts and soil conditions for certain areas. A hydrograph study using an instantaneous unit hydrograph provides a good approach for hydrologic research since the short duration of effective rainfall is close to the duration caused by an instantaneous burst of rainfall. The study also synthesizes the parametric hydrograph which simplifies hydrograph analysis.


Technical Report No. 43
ARTIFICIAL RECHARGE PRACTICES IN HAWAII

David R. Hargis, Frank L. Peterson
October 1970

ABSTRACT
In July of 1969 the Water Resources Research Center began an investigation of artificial recharge practices in Hawaii. The objectives of this study were: (i) to compile all sites in the State where artificial recharge has been practiced, (ii) to provide quantitative information, on the amounts of water recharged, and (iii) to evaluate, where possible, the effectiveness of the various methods of artificial recharge that have been used in Hawaii. Artificial recharge practices in Hawaii include all of the following: (i) stream-water recharge through wells and shafts, (ii) storm drainage disposal through wells and pits, (iii) induced leakage from ditches and reservoirs and deliberate spreading of excess irrigation water, (iv) incidental ditch and reservoir Leakage and other nondeliberate recharge of irrigation water, and (v) cesspool seepage. The most significant source of artificial recharge to groundwater bodies in Hawaii is probably recharge incidental to irrigation. The volume of water recharged in this manner can be calculated from hydrologic budget considerations, but such calculations are limited in their reliability by a general absence of comprehensive data. Seepage from cesspools has probably contributed significant amounts of recharge to ground-water bodies in Hawaii and these amounts can also be determined by hydrologic budget considerations. Deliberate artificial recharge to ground-water bodies in Hawaii consists of wells recharging stream water at Hanapepe, Kauai and Puukapu, Hawaii, welts and pits which dispose of storm drainage at Wailuku and Kahului, Maui and Hilo, Hawaii, and excess irrigation water by induced Leakage from ditches and reservoirs and water spreading over fields and in gulches at Hawaiian Commercial and Sugar Company on the East Maui isthmus. In addition, the Department of Land and Natural Resources of the State of Hawaii will begin disposal of treated sewage through three deep wells at Waimanalo, Oahu as soon as sewerage is completed.


Technical Report No. 44
IDENTIFICATION OF IRRIGATION RETURN WATER IN THE SUB-SURFACE, PHASE III: KAHUKU, OAHU AND KAHULUI AND LAHAINA, MAUI

Pedro A. Tenorio, Reginald H.F. Young, Nathan C. Burbank, Jr., L.Stephen Lau
December 1970

ABSTRACT
This study continued the joint research effort undertaken by the Water Resources Research Center and the Honolulu Board of Water Supply in 1967 to investigate the physical and chemical characteristics of irrigation return water. Initial work concentrated on the Pearl Harbor Waipahu area of Oahu. The phases reported herein included both Kahuku Plantation on Oahu and the sugar cane cultivation areas of central and West Maui (Pioneer Mill Co. and Hawaiian Commercial and Sugar Co.). Composite well, spring, and stream samples were taken and analyzed in the Laboratory for the following constituents: bicarbonate, calcium, magnesium, phosphate, silica, boron, chloride, nitrate, sodium, potassium, bromide., fluoride, sulfate, and total hardness. On the basis of increased index constituents over uncontaminated ground-water sources used to identify the presence of irrigation return water, it is evident, as previously concluded by Visher and Mink (1964), such irrigation return water, is definitely present in the basal water bodies underlying the three study areas. Considerable increases in the nitrate and sulfate indices, especially, and in the bicarbonate and silica indices, as shown by various methods of interpretation of water quality data obtained over a period of approximately two years or exceeding one complete cycle of planting and harvesting of sugarcane, verify the strong influence of irrigation and agricultural practices in altering the overall quality of the basal water sources in the three areas. The basal water quality of the HC&S aquifer is most affected regionally, as well as locally, by the prevailing agricultural practices. The deterioration of the water is due in part to fertilization and to a greater extent to heavy pumping and recycling of the basal water. Water quality in the Pioneer Mill area parallels that of HC&S, although on a regional basis, the basal water quality, unlike that of the Pioneer Mill area, is not as deteriorated. Local effects of pumping are also especially noticeable in the Pioneer Mill area. Ground-water quality in the Kahuku area shows the obvious presence of irrigation return water indices, but, unlike the two plantations on Maui, the magnitude of the increases relative to uncontaminated water sources is considerably smaller. The effect of fertilization on Kahuku may be considered to be a principal factor in the regional distribution of index constituents with a relatively uniform nitrate distribution throughout. Local effects of pumping are quite pronounced and influence overall increases of indices, indicating that where heavy pumping takes place for irrigation, the increase in index constituents are correspondingly greater.


Technical Report No. 45
DENSITY LOGS FROM UNDERGROUND GRAVITY SURVEYS IN HAWAII

Richie D. Huber, and William M. Adams
February 1971

ABSTRACT
The gravity method has been applied in three wells in Hawaii to estimate density and porosity logs. The wells are the Schofield shaft on the island of Oahu, the Kihei #3 shaft on the island of Maui and the Pahala shaft on the island of Hawaii. The method determines the “averaged” density and porosity values for Hawaiian rocks. On Oahu, the density at depth is 2.4 gm/cc and the corresponding porosity is 18 percent. For Maui, the density averages about 2.4 gm/cc and porosity at 17 percent. The Hawaii shaft shows a lower density of 2.0 gm/cc with a correspondingly higher porosity of 27 percent. All these values are based on a grain density of 2.9 gm/cc.


Technical Report No. 46
INTERPRETATION OF ELECTRICAL RESISTIVITY LOGS IN A TWO-ZONE CYLINDRICALLY SYMMETRIC GEOMETRY

L. J. Shamey, W. M. Adams
March 1971

ABSTRACT
A two-zone theoretical model, consisting of a cylindrical bore hole filled with drilling mud and surrounded by homogeneous, isotropic rock, was studied to aid interpretation of electrical resistivity logs. Apparent resistivities are numerically calculated as a function of the rock and the drilling mud resistivities and the separation of the electrodes on the coaxial measuring sonde. For practical use, the inverse, interpretation problem must be solved. Therefore, graphs for finding the true matrix resistivity–given the hole diameter, mud resistivity, and electrode spacings–are presented for ranges applicable to Hawaiian conditions. The interpretation may be done with the interpolative digital computer program provided.


Technical Report No. 47
GROUND-WATER RESOURCES AND DEVELOPMENT: COASTAL PLAIN REGION ERH JEN CHI–KAOSIUNG, TAIWAN

L. Stephen Lau, John F. Mink, Chester Lao
May 1971

ABSTRACT
A 200 square kilometer representative area of the coastal plain of southwestern Taiwan was selected for a cooperative pilot ground-water study to identify and provide methods and knowledge that are essential and appropriate for the evaluation of ground water resources and development in Taiwan. The project was jointly sponsored by the Taiwan Sugar Corporation and the Sino-U.S. Joint Commission on Rural Reconstruction. The work was conducted as a cooperative effort of the personnel of the Taiwan Sugar Experiment Station at Tainan and the Water Resources Research Center, University of Hawaii. The pilot study area is located on a coastal plain intensively cultivated for sugar cane, rice, and other crops and is apparently water deficient. Some surface water is used for irrigation, but ground water is more widely used. Existing basic data pertinent to the study were collected, collated, and evaluated and augmented by data developed by the project. The zone of active ground-water circulation is essentially restricted to a relatively thin very fine to fine grain sand of the Tainan formation averaging 10 meters in thickness. Over most of the project area the aquifer is confined or partially confined by clay except at Nan Tzu where water-table conditions prevail. The aquifer is essentially not continuous over the entire coastal plain. Its permeability averages about 10 meters per day but can be occasionally as high as 200 in the lithic coarse sediments found near the foothill areas. Underlying the aquifer is the Gutingkeng formation which consists predominately of thick dark clays with minor fine sands. This formation is of marine origin and contains residual saline water and exhibits no known evidence of extensive fresh water. Present ground-water development consists of numerous shallow wells, most of them tapping the Tainan Formation. The numerical densities of water wells concentrate in the vicinities of the villages of A Lien and Chu Hu, the area west of Chia Tien, and the areas surrounding Nan Tzu. Contemporaneous sea-water intrusion from coastal areas has not been observed, but the residual saline water imposes a constraint to the quality of the aquifer under stress. Hydrologic budget and supplementary flux computations indicate that the natural ground-water recharge coupled with the existing importation can satisfy the supplementary irrigation water requirements even if the entire arable land in the area is cultivated. Low aquifer transmissivity coupled with high well loss were demonstrated through analysis of pumping tests and operational data. The expected optimum yield for a well field and the attendant drawdown demonstrate that numerous wells of low to moderate yield, carefully designed, constructed and maintained, will be best suited for developing the additional ground water. The terrace and alluvial fan area were recommended for future exploratory studies as were other specific studies for the major aspects of this study: geologic, hydrologic, geochemical, and developmental.


Technical Report No. 48
DIRECT DETERMINATION OF THE ELECTROMAGNETIC REFLECTION PROPERTIES OF SMOOTH BRACKISH WATER TO THE CONTINUOUS SPECTRUM FROM 10 8 TO 4 x 10 9 HERTZ

Larry K. Lepley, William M. Adams
May 1971

ABSTRACT
A new geophysical technique for the remote measurement of the electromagnetic properties of natural surfaces was investigated. Theoretical and laboratory work has produced evidence for the validity of the use of ultra-high frequency radio reflection spectrometry for remote sensing of salinity of brackish water. A preliminary study of the electromagnetic properties of aqueous sodium chloride, computer-generated frequency dispersion curves of 1) the dielectric coefficients, 2) power reflectance, 3) brightness temperature, and 4) skin depth of water as a function of eight different normalities of sodium chloride, corresponding to a salinity range from pure to ocean water and as a function of five different temperatures from 0oC to 40oC to the radio frequency range from 106 to 3 x 1010 Hertz were constructed. These graphs indicate that the frequency dispersion of the reflectance of radio energy in the 106 to 109 Hertz band at normal incidence to a smooth water surface is strongly influenced by the salinity of the water, and that the spectral signature could be used as a measure of water salinity as distinguished from water temperature. In the range of interest, 20oC to 25oC, 0.3 ppt to 30 ppt dissolved solids, the dominant physical factor explaining the change of reflectance with salinity changes is the ionic conductivity due to the lateral flow of ions induced by the imposed electromagnetic field. The ionic conductivity of brackish water is a monotonic function of the salt content. A laboratory prototype radio refection spectrometer was designed and assembled from commercially available swept-frequency UHF-microwave test equipment, a single horn antenna, and a hand-made coaxial sample cell. Reflectance spectra from 2.5 x 109 to 4.0 x 109 Hertz of fresh and sea water were obtained with a free-wave (horn antenna and pool) system and reflectance spectra of brackish and sea water from 108 to 2.0 x 109 Hertz and of fresh water from 0.8 x 109 to 2 x 109 Hertz were obtained with a coaxial waveguide system. The measured spectral signatures appear to agree with the computed reflectance of aqueous sodium chloride solutions.


Technical Report No. 49
THERMAL PROPERTIES OF SEA WATER

James C. S. Chou
July 1971

ABSTRACT
The interpolation formulae for vapor pressures, specific volumes, enthalpies and heats of vaporization of ordinary sea water have been determined in the temperature range Oo to 200oC for salinities of 0 to 120 ppt, based on the published data. These formulae may facilitate calculations for designing desalting evaporators. The accuracies of vapor pressure data were found insufficient; however, the accurate measurements of vapor pressures by others are in progress. A close correlation was found between the compressibilities of sea water and those of aqueous sodium chloride solution at low temperatures. Because the lack of experimental data on compressibilities of sea water at elevated temperatures, compressibilities of aqueous sodium chloride solution for pressures up to 350 atmospheres are used as approximations to those of sea water in order to account for the effect of pressure on other thermal properties.


Technical Report No. 50
BIBLIOGRAPHY OF WATER RESOURCES OF THE HAWAIIAN ISLANDS

Rose I. Pfund, Dorothy l. Steller

July 1971
PREFACE With the accelerating accumulation of scientific knowledge and engineering works, tremendous problems have arisen with the efficient storage and retrieval of information. Even in the individual basic laboratory sciences there is an ever-growing amount of duplication of efforts due to the relative difficulty of tracking down past research and to the attractions of work in the laboratory relative to search in the archives. In the applied natural sciences and engineering, the problems are much worse because the experimental field is likely to be contaminated by previous experiments and developments, often poorly documented, and the search for records is likely to be complicated by multiplicity of the scientific and professional disciplines involved. It seems obvious that increasing efforts must be put into the various forms of systematization of scientific and engineering records, including specialized bibliographies. The term specialized deserves some explanation, because a bibliography, to meet a specialized need, is likely to represent much more than a restricted selection from some more general bibliographic area. Its restrictions in some directions are likely to be more than compensated by its expansions and generalizations in others. Pertinent to the field of the water resources of the Hawaiian islands there have been several previous bibliographies, but they are mostly out of date, and there are great gaps among their coverages. The need for a comprehensive, up-to-date, annotated bibliography was recognized soon after the Water Resources Research Center began to function in 1965. Though essential, bibliographic work proved difficult to fund in comparison with new research, and the process of compiling this bibliography was hence a lengthy one.


Technical Report No. 51
THE RESPONSE TO TIDAL FLUCTUATIONS OF TWO NON-HOMOGENEOUS COASTAL AQUIFER MODELS

John A. Williams, and Ta-Chiang Liu
September 1971

ABSTRACT
Mathematical and electric analog (R-C circuit) models for two one-dimensional non-homogeneous coastal aquifers have been developed. The first is a semi-infinite aquifer having a discontinuous change in permeability at a distance L from the coastline and the second is an aquifer of length L whose permeability changes linearly with distance from the coastline and whose interior boundary represents either a constant head or a no-flow condition. Both models were subjected to a sinusoidal tidal input. Results, in the form of graphs of amplitude and phase angle vs position, show excellent agreement between the outputs of the mathematical and electric analog models. In the case of a discontinuous permeability, these graphs indicate a positive or negative reflection from the discontinuity for a decrease or increase, respectively, in the permeability. In the case of the linearly varying permeability model, the graphs of amplitude indicate that energy is attenuated at a greater rate near the coastline-when KL/KO, <1 for both types of boundary condition. Graphs of the phase angle are concave downwards for the constant-head boundary condition but for the no flow condition they exhibit a point of inflection whose position depends on tO and KL/KO. Electric analog model results show that for the semi-infinite aquifer no significant error will result from the circuit configuration if a < A/50 and the circuit length is equivalent to 2A, furthermore, “lumped” components, i.e., a = A/5, may be used to extend the circuit beyond x = -.4A if measurements are restricted to x > -.2/A.


Technical Report No. 52
SLUDGE DIGESTION PRACTICES ON OAHU, HAWAII

Jeong-rong Chen, Reginald H.F. Young
Center for Engineering Research

ABSTRACT
Characteristics and treatment efficiency of the sludge digestion facilities at four sewage treatment plants of the City and County of Honolulu, one each at Kaneohe, Kailua (both secondary treatment-trickling filter plants), and Pearl City (primary treatment), which utilize anaerobic digestion system and the fourth at Mililani (secondary treatment-activated sludge), which utilizes an aerobic digestion system were studied over a two-week period at each plant. Included in the study were both raw and digested sludges.

Overall results indicate that the digestion systems were operating generally within accepted ranges for parameters tested. The Kaneohe plant had a volatile solids reduction of 64 percent, solids retention time of 143 days, and methane: carbon dioxide gas yield percentage off 67:33. The Kailua plant had a volatile solids reduction of 30 percent, solids retention time of 32 days, and methane: carbon dioxide gas yield percentage of 66:34. The Pearl City plant had a volatile solids reduction of 64 percent, solids retention time of 10 days and methane:carbon dioxide gas yield percentage of 64:36. The Mililani plant had a volatile solids reduction of 49 percent with a sludge age of 36 days.
It was concluded that the three anaerobic digestion systems were operating satisfactorily although not at optimum efficiency. The Mililani plant achieved a reasonable digestion efficiency although operational problems were indicated because of low pH and ORP values for the sludge and high specific resistance values for the digested sludge.
It was recommended that a program of regular monitoring of sludge characteristics and digestion treatment efficiency be initiated to assist in plant operations at all sites


Technical Report No. 53
TRITIUM AND RADIOCARBON IN HAWAIIAN NATURAL WATERS; PART I

Theodorus H. Hufen, Robert W. Buddemeier, L.Stephen Lau
April 1972

ABSTRACT
A field investigation was undertaken to establish the present tritium and radiocarbon activity levels of natural waters found in various parts of the island of Oahu. The instrumentation required for the radiocarbon analysis was assembled and workable procedures were developed. Monthly rainwater samples obtained from rain gages on the Koolau Range contained seasonally fluctuating tritium concentrations which are well in excess of the natural abundance level. Excess concentrations were also found for the tritium and radiocarbon content of surface waters from three separate sources. These excess concentrations are the result of fallout from atmospheric nuclear explosions. Samples from nine tunnels, which tap various Koolau dike compartments, contained tritium activities ranging from the current rainwater levels down to the pre-nuclear explosion levels. Most samples showed radiocarbon activities comparable to pre-explosion atmospheric C02 levels. Two samples, however, showed excess radiocarbon. Samples from wells and shafts tapping basal water in the Honolulu area generally showed little or no tritium and their radiocarbon concentrations were lower than those of the dike-water samples. Makiki, Booth, and Roseapple Springs, which discharge perched water, exhibited tritium levels slightly in excess of the contemporary rain water levels. Nuclear explosion radiocarbon was present at Makiki Spring whereas it was absent at Booth Spring. Correlations between radiocarbon and chloride content were found for samples from Central Oahu and the Pearl Harbor area. The magnitude of both constituents were moreover a function of the distance between the sample source and Pearl Harbor. Three multiple depth samples from well T-133 at Ewa Beach showed very low radiocarbon content. These results can be evidences of radioactive decay of the radiocarbon thus indicating very long residence times of these waters. Exchange reactions between the water-carbonates and the radiocarbon-free aquifer carbonates can lead to the same results however. The discovery of a linear relationship between the radiocarbon activity and chloride contents of these samples indicates that chemical exchange reactions have taken place.


Technical Report No. 54
EFFECT OF STORM RUNOFF DISPOSAL AND OTHER ARTIFICIAL RECHARGE TO HAWAIIAN GHYBEN-HERZBERG AQUIFERS

Frank L. Peterson, David R. Hargis
November 1971

ABSTRACT
Artificial recharge for the purpose of replenishing the fresh ground-water body in Hawaii has been deliberately practiced in a few areas for many years, and has been recognized as incidental to other practices, principally irrigation, in many areas for several decades. The effects of these various artificial recharge practices on Hawaii Ghyben-Herzberg aquifers are briefly described in this report. In recent years, the practice of artificially recharging wastewater such as storm runoff, sewage effluent, and various industrial wastes into the subsurface has become of growing importance in Hawaii. In 1970 the Kahului Development Company began construction of a collecting basin and four deep injection wells for the disposal of storm runoff from a residential development in Kahului, Maui. This presented a unique opportunity to evaluate the suitability of the site for artificial recharge and to study the possible effects recharge of storm runoff might have on the local ground-water body, both from a water quality and a hydraulic standpoint. Studies were made to determine the following information: (i) the concentrations of selected chemical and biological parameters in storm runoff from residential areas in the town of Kahului and in the ground-water body in the area of the collecting basin and injection wells for the purpose of predicting the effects of artificial recharge of storm runoff on the water quality of the existing local ground-water body, (ii) the injection rates that can be expected for the completed injection wells by means of pumping and injection tests, and (iii) the movement of the injected water by monitoring water levels and selected chemical and biological parameters at observation wells near the injection site. The results of pumping and injection tests of one completed well and one test hole indicate that the finished injection wells should be able to inject at rates in excess of 5500 gallons per minute per well if significant clogging from sediment does not occur, and if hydraulic interference between the four wells operating simultaneously is not significant. Water analyses indicate that quality of the storm runoff from the Kahului area is generally good, with low dissolved solids and low chloride concentrations. Some fecal coliform will undoubtably be introduced into the aquifer during injection of storm runoff. However, dilution of the injected runoff by the ground water and the hostile environment presented by the saline water in the disposal zone should eliminate any bacterial hazard. The most serious potential water quality problem may be a reduction in injection efficiency owing to possible well clogging by heavy sediment loads. The general water quality effects of injecting storm runoff into the ground-water body will be to decrease the dissolved solids concentration of the ground water in the vicinity of the wells.


Technical Report No. 55
A PRELIMINARY SURVEY OF PUBLIC WATER-RELATED AGENCIES IN HAWAII

Eamon T. Morahan, and Hiroshi Yamauchi
May 1972

ABSTRACT
The governmental structure of Hawaii through which its water-related agencies operate is a relatively simple one as compared to that of most other mainland states. A highly centralized state government dominates over one layer of four county-level governments (in the case of Honolulu, the City & County of Honolulu). Each of these four local governments has its own charter which is similar in most respects to the others, but, nevertheless, uniquely applicable to itself. County boundaries are conveniently contiguous with the natural geographic boundaries of each island except for the tri-islands county of Maui (Maui, Molokai, and Lanai). Besides the four island counties, the only other local-level governmental entity is the Soil and Water Conservation District. There are some 15 of these SWCD’s covering about 96 percent of the land area in the state. They, however, do not possess any taxing or regulatory powers and for administrative purposes they are closely associated with the State Department of Land and Natural Resources. While it is generally conceded that Hawaii has a relatively simple governmental structure, there is nevertheless a considerable number of public water-related agencies that has evolved over time. Some 50 odd agencies have been conveniently categorized under federal, state, and local agencies. While not all the higher level agencies in the federal category such as, the Water Resources Council, the Council of Environmental Quality, the National Water Commission, and the Office of Management and Budget, are physically represented in Hawaii, they still have important bearings on the water policies and programs of the state and so have been usefully considered along with those situated in the islands. Despite this broadened scope, the institutional coverage in this report is still somewhat limited by the fact that, except for the three quasi-public companies which come under the purview of the State Public Utilities Commission, only public agencies were surveyed. Also, since the agencies are for the most part entities of the executive branch of the government, the roles of the legislative and judicial branches are likewise not adequately reflected. These public water-related agencies may then be regarded as only a portion of a complex institutional superstructure that functions in the water economy of Hawaii. Conceptually, this institutional superstructure is just as much a part of the total water resource system in Hawaii as the physical sub-system itself. From a social viewpoint, the physical sub-system exists for the ultimate benefit of mankind who has, through experience in conflicts, systematically developed the necessary institutions to facilitate orderly development and use of his naturally endowed water resources. in this sense, both the physical and institutional subsystems make up the total integrated water resources system of the state.


Technical Report No. 56
ESTIMATING THE PRODUCTIVITY OF IRRIGATION WATER FOR SUGARCANE PRODUCTION IN HAWAII

Lloyd B. Rankine, Jack R. Davidson, Howard C. Hogg
June 1972

ABSTRACT
This study has concentrated on the development of an operational model for determining the productivity of irrigation water in sugarcane production in Hawaii. Data were collected from sugar plantations located in two sugar-producing areas chosen to represent the various sugar-producing conditions in the state. Area I depended exclusively on water from artesian wells for irrigation. Irrigation in Area II depended mostly on stored surface runoff rainfall and is supplementary in nature. Both areas differ in their physical terrain. Of necessity, the study draws heavily from and builds on the experiences of previous investigations in the general areas of agricultural economics and plant sciences. From an integration of these ideas, the modified composite variable was developed as a measure of water adequacy in cane production. Most of the information required to construct this variable is available from management records. Pan evaporation data were incomplete because standard evaporation pans were only recently installed and then only in a few areas. To overcome this difficulty, techniques were developed to estimate evapotranspiration for the two study areas utilizing available pan data together with other relevant indicators.


Technical Report No. 57
HAWAII’S SYSTEM OF WATER RIGHTS: AN ECONOMIC EVALUATION

Eamon T. Morahan, and Hiroshi Yamauchi
HAES Journal Series No. 1511 – August 1972

ABSTRACT
Hawaii’s system of water rights consist of a “bundle of rights” which are variously attached to fresh surface waters and to artesian ground waters. Surface water rights are for the most part “unique” to Hawaii and are based on ancient customs and traditions of the islands. on the other hand, the correlative rights doctrine which applies to most ground-water basins in the western world also applies (since 1929) to artesian ground waters in Hawaii. In general, Hawaiian surface water rights are fairly well defined and offer greater investment security than the correlative rights doctrine with its inherent tenure uncertainty. Unlike the case of the correlative rights doctrine, flexibility for surface water reallocations to alternative uses is not necessarily gained at the expense of security.


Technical Report No. 58
A STUDY OF WATER INSTITUTIONS OF HAWAII

Eamon T. Morahan, and Hiroshi Yamauchi

HAES Journal Series No. 1480 – August 1972

ABSTRACT
The structure, functioning and performance of water institutions in Hawaii is studied within a “hierarchy of decision-levels” framework developed by S.V. Ciriacy-Wantrup. The study framework provides new opportunities for gaining insights into the economic nature of water institutions from the standpoint of water policy.


Technical Report No. 59
WATER QUALITY OF KAPALAMA CANAL

Reginald H.F. Young Sung Duck Hahn, Jerry M. Johnson
September 1972

ABSTRACT
A water quality survey of the Kapalama canal was undertaken in 1970 – 1971 to obtain baseline data for evaluation of the pollution potential of that surface drainage channel. The survey included the stretch of canal between the residential area below School Street to the tidal waters downstream of the pineapple canneries effluent discharge ditch. Chemical and bacteriological characteristics of the Canal were assessed through the measurement of the following parameters: pH, DO, alkalinity, hardness, chlorides, total solids, total nitrogen, total phosphorus, BOD5, total coliforms, fecal coliforms, fecal streptococci and Pseudomonas aeruginosa. Results of the survey show that levels of all parameters except pH and alkalinity increased in a downstream direction with high levels particularly noted downstream of the tidal dam, probably due to the effects of effluent discharge from the pineapple canneries outfall ditch. A significant diluting effect was noted during periods of wet weather streamflow. The state water quality standards were exceeded for several parameters: pH, DO, nitrogen and phosphorus in the Class A waters, and total coliforms in both the Class A and Class 2 waters. The average FC:FS and FC:TC ratios for the Class 2 waters were 5.2:1 and 0.25:1, respectively. The high FC:FS ratio indicates that human wastes as well as animal feces are entering Kapalama Canal. Pseudomonas aeruginosa organisms were found in the canal waters and were observed in densities greater than attributed to stormwater runoff in the literature.


Technical Report No. 60
THE QUALITY OF COASTAL WATERS: FIRST ANNUAL PROGRESS REPORT

Sea Grant program, year 04 Project Principal Investigator L.Stephen Lau
Sea Grant Program No. UNIHI-SEA GRANT-72-01 – September 1972

ABSTRACT
The nature and results of the first year of experimental and evaluative work of the Coastal Water Quality project of the University of Hawaii’s Sea Grant Program are summarized in this report. The project is a multi-directional, multi-disciplinary study directed to the general objectives of identifying and evaluating the social, political, economic, educational, institutional, and scientific and technological factors which impede or expedite the protection and restoration of coastal water environments in Hawaii, as well as of developing the crucial scientific and rational parameters needed in formulating effective policies institutions and systems. To this end, the attainment of eight specific objectives is assigned to appropriate faculty specialists participating in 14 activities which comprise the Project. These specialists have the additional duty of assisting the Principal Investigator in planning the work and in interpreting its results in terms of the general objective. The project is unique in that it seeks to evaluate water quality in terms of stress or well being of aquatic communities, using the traditional chemical, biological, and bacterial parameters of water quality only to identify the factors and their concentrations which are of ecological significance. in turn the ecological findings are utilized to refine the standards and criteria applicable to traditional parameters. Kahana Bay was selected as a coastal water under the influence of relatively undeveloped land. Data already available on the physiography and hydrology of its drainage area, its estuarine and oceanographic aspects, and the nature and movement of its sediments were supplemented by a program of analysis of water and sediments and its biota. As in all situations especial attention was given to the pesticides, heavy metals, and nutrients in water and sediment and to evidence of stress on aquatic communities. Significant findings, which will, if further substantiated, be of value to regulatory agencies of the State, are that only when diluted heavily with fresh water did the dissolved oxygen content in the estuary meet the class AA standard designated for Kahana waters and the phosphorus content was mostly at class AA level (0.02 mg/l) but this value was exceeded seasonally. Nitrogen, and coliform organisms showed a similar., although more variable pattern. Thus Kahana Bay tended to satisfy the class A standards rather than the class AA standards for which the Bay is classified by the State. DDT and PCB (pesticides) in Kahana Bay waters and sediments appeared at levels which seem to be ubiquitous in nature. Heavy metals, particularly Pb, Cd. Zn, and Cu appeared in the sediments in no identifiable pattern and apparently depend on the parent geologic formations from which the sediments are derived. Sugarcane production and milling wastes were studied on Kauai. Observations of mill waste discharge and coastal water, sediments, and biota were made both before and after the 90-year old Kilauea Sugar Company closed down its operations in north Kauai. Untreated mill wastes were found to be the major contributor of wastes from the industry, carrying coliforms, sediments, trash and bagasse. The effect was largely an extensive visible plume and debris in the waters. Sediments, rather than water, harbored most of the nutrients, heavy metals, and pesticides in the ocean. DDT, although not used by the sugarcane industry, was present in small amounts in all waters and sediments. Herbicides used in sugarcane culture did not appear in coastal water. A striking improvement in the aesthetic aspects of the coastal water quickly followed the cessation of mill waste discharges. Fish and other aquatic biota reappeared rapidly after the cessation of mitt operations. Longer term changes in the biota are yet to be assessed. Studies were begun in south Kauai late in the report period to assess the effect of changed operational practices by the McBryde Sugar Company subsequent to an EPA survey of coastal waters of the area in 1968. Company practices demonstrate that it is possible to operate milling operations without discharge to the ocean, and to prevent irrigation tailwater overflows except flooding due to intense rainfall. At the time of reporting no pesticide residues were found offshore except for the 1 part per trillion DDT which seems to be present everywhere. Studies by others on the Hamakua Coast and elsewhere generally show reduction in abundance of biota within the area (perhaps one mile) where waste sediments from mill discharge blanket the normal bottom. The effects of urban wastewater especially sewage, were studied during the report period largely by cooperating with the City and County of Honolulu and the federal agencies in Hawaii engaged in major investigations and projects such as sewage treatment at Sand Island, Pearl Harbor, Kaneohe Bay, and Mokapu Point. The role of the Coastal Water Quality Project in these major enterprises are described in the report. In less extensive situations at Sandy Beach, Waikiki, Maunalua Bay, and Manoa Stream, the Project is amassing data for the effects on the coastal environment of surface runoff and general human activities in urbanized areas. preliminary findings are included in the report. The overall objective for the identification and evaluation of the separate effects of various land uses on the quality of coastal waters is to interpret them in terms of changes in the institutional, economic., and social systems needed to achieve the environmental objectives of the state. To enable researchers to begin this aspect of the study, statutory changes and the zones of mixing that have been granted since 1967, when the federal-state water quality standards were adopted, have been compiled. By continuing to tabulate such institutional changes, the opportunities to integrate relevant scientific knowledge into social policy will be enhanced.


Technical Report No. 61
A RAINFALL CLIMATOLOGY OF HILO, HAWAII

Charles M. Fullerton
UHMET 72-03 – December 1972

ABSTRACT
Annual, monthly, and hourly rainfall data for Hilo, Hawaii are plotted and analyzed as a preliminary phase of the study of space-time variations in high intensity rainfall in this locality. A brief summary of the Hilo climate is provided. Annual rainfall amounts are shown to be highly variable, while the annual rainfall frequency remains relatively constant at about 33 percent. Monthly rainfall and maximum 24-hour rainfall amounts are displayed in the form of a monthly rainfall expectancy graph. Hourly rainfall amounts are divided into four intensity categories: 0.01 – 0.24, 0.24 – 0.49, 0.50 – 0.99 and > 1.00 inches per clock hour. The percentage distribution of annual and monthly rainfall amounts and frequencies by rainfall intensity category are plotted and discussed. Hourly data are displayed in a series of monthly diurnal distributions by rainfall intensity category.


Technical Report No. 62
WATER RECYCLING OF SEWAGE EFFLUENT BY IRRIGATION: A FIELD STUDY ON OAHU

First Progress Report for August 1971 to July 1972

Project Principal Investigator – L.Stephen Lau Co-Investigators: Soil and Irrigation Studies – Paul C. Ekern, Virology Studies – Philip Loh, Water Quality Analysis – Reginald H.F. Young, Overall Data Studies – Gordon L. Dugan – November 1972

ABSTRACT
An investigation of recycling sewage effluent by irrigation under Hawaiian conditions is being conducted in pilot field studies near Mililani Town in central Oahu under the sponsorship of the Board of Water Supply and the Division of Sewers, City and County of Honolulu. The primary objective of the project is to determine the feasibility of wastewater application to the soil and its probable effects on the quality of ground water in terms of dissolved materials and viruses. Corollary objectives are to ascertain its effects on sugarcane yield and grass lands. The studies began in-September 1971 with the construction of a five-foot deep hydraulic lysimeter in a grassed area on the grounds of the Mililani sewage treatment plant. The upper surface of the lysimeter was at ground level. Soil within the lysimeter was repacked to the approximate original density. In an adjacent site, a number of two-foot square pans were placed at various depths down to five feet in undisturbed soil adjacent to an access pit. The lysimeter and pan areas were sprinkler-irrigated with secondary sewage effluent from the Mililani sewage treatment plant on a regular schedule. Five furrows of maturing sugarcane in a nearby field were also irrigated with the secondary effluent while the adjoining furrows continued to receive regular irrigation water. Numerous point water samplers were positioned in both furrows and ridges of the sugarcane field at depths to 33 inches. The soil within the test sites of both the grass and sugarcane areas is of the oxisol Lahaina series, the general type on which approximately 90 percent of Hawaii’s irrigated sugarcane is grown. Raw sewage, secondary effluent, and leachate from the soils were assayed for various physical, chemical, sanitary, and microbiological quality parameters. Analyses for pesticides and heavy metals were also occasionally performed. A virus laboratory, the first of its kind in Hawaii, was established at the University to serve the project and to assist in training the personnel of the Board of Water Supply. Soil samples were analyzed periodically for changes in their mineral composition. Consumptive use of water was determined by use of the hydraulic lysimeter. Operational analyses showed that the Mililani sewage treatment plant, which employs the activated sludge process, is capable of removing a high percentage of the biodegradable substances and suspended solids as well as a surprisingly high percentage of nitrogen, a nutrient ordinary secondary treatment plants are not designed to remove. The sewage effluent was void of detectable mercury (less than 0.3 parts per billion) and the cadmium and lead were less than the Public Health Service drinking water standards. Pesticides were found to be less than 1 ppb. With the possible exception of the sodium percentage, the effluent appears to be of good quality for agricultural irrigation use. The soil at Mililani appears to be very effective in removing BOD5, TOC, nitrogen, phosphorus, potassium, boron, and coliforms as evidenced by analyses of the leachate passing through the five-foot deep lysimeter. Nitrogen, however, was not effectively removed until after five months of operation, whereas, the other constituents exhibited fairly rapid attenuation. There appeared to be evidence of a base exchange or similar phenomenon in the soil at least between sodium and calcium in Oahu Sugar Company sugarcane field No. 240. Similar results were also found for the leachate collected by the point samplers in the sugarcane fields. Virus cultures were obtained from the sewage effluent before chlorination and identification is presently (August 1972) proceeding. To date, data have been limited to those collected over a period ranging from several months in some instances to only one or two months in others. Thus, it is too early to formulate any definitive conclusions or to predict the concentrations of the various constituents which might be expected, especially since the full seasonal effects have not been determined.


Technical Report No. 63
WASTEWATER EFFLUENTS AND SURFACE RUNOFF QUALITY

Michael J. Chun, Reginald H. F. Young, George K. Anderson
November 1972

ABSTRACT
A three-year study was conducted to determine the quality of domestic wastewater treatment plant effluents and urban surface runoff, including street litter, on Oahu and to examine the reclamation potential of these water resources. The study was conducted in three phases: 1) the examination of effluents of eleven wastewater treatment plants representative of conventional treatment technology, 2) the characterization of street Litter and of runoff from a watershed representative of runoff from varied land-use patterns, and 3) the fabrication of a reverse osmosis pilot module and preliminary evaluation of its potential to reclaim secondary sewage effluent. Domestic sewage flows were found to be characteristically similar to those found elsewhere in the United States. Treatment plant efficiency in reduction of organic matter and suspended solids, for all process trains studied, was comparable to reported literature. Effluent nutrient (N and P) and dissolved oxygen levels do not meet standards of receiving water quality suggesting a need for mixing zone variances, process change or addition or both. Reclamation of the effluents for recharge or direct reuse schemes should be within the capabilities of present technology. Manoa Stream was selected for the watershed study. Results show generally very low levels of all parameters as compared to wastewater effluents but an extreme range of variability dependent on flow conditions. Constituent levels or “degree of contamination” were found to vary directly with urban population density, urban development and land-use activity. The most significant factor determined was that in both dry and wet weather conditions, the State Water Quality Standards. However, low fecal coliform to fecal streptococcus ratios indicate the probable source of bacterial contamination as non-human, warm-blooded animals and thus the stream waters may still be considered suitable for recreational use. Street sweepings were obtained from locations of urban activity in downtown Honolulu and Waikiki. Compared to data available from a Chicago study, these street litter had a higher BOD, nitrate, phosphate, and water soluble material content. Results showed a considerable potential for pollution of surface runoff by the street litter but this impact requires further evaluation since the litter was obtained by sweeping of only the gutter areas, not the entire paved street surface, and may not be totally representative of the suspended and dissolved materials load that may be transported with runoff into stormwater collection systems. In the final phase of study a spiral-wound test module reverse osmosis unit was fabricated for evaluation in reclamation of wastewater effluents. The effluent was selected over runoff or streamflow because of its relative constant flow volume. Initial test results with intermittent operation of over 320 hours yielded a product comparable to a low mineral content water supply from chlorinated activated sludge effluent. Reduction in flux rate occurred, however, necessitating the use of an enzyme detergent flushing to restore the unit’s production capacity, but the flux rate could not be restored to its original operating level. Continued testing of the unit is planned with effluents of different degrees of wastewater treatment to better determine its treatment capabilities and economics of operation.


Technical Report No. 64
A PRELIMINARY REPORT ON FLOOD HYDROLOGY AND URBAN WATER RESOURCES: OAHU, HAWAII

Yu-Si Fok
March 1973

ABSTRACT
Studies conducted during Phase I of the “Flood Hydrology and Urban Water Resources of the Island of Oahu, Hawaii” project, were divided into four major tasks. The first is an examination of the causes of flooding and flood damages on Oahu. This task has been completed and data obtained reveals that historical floods in Oahu happened most frequently within the city limits of Honolulu and the Waialua area. Watersheds in Honolulu such as Kalihi, Manoa, Makiki, Moanalua, Nuuanu, Palolo and Pauoani were found to have frequent floods up to the 1940’s; however, they have not been subjected to severe frequent floods for the past two decades. Watersheds such as Kailua, Kaneohe, and Waimanalo in Windward Oahu and Aina Haina, Niu Valley, and Pearl City on the fringes of the city limits of Honolulu were reported to have more frequent floods in the past two decades. Some of the reason for the patterns of flooding are: 1.The Honolulu district has the highest concentration of people and housing on the island. 2.The Waialua area is located downstream of many large streams of the island. 3.Kalihi., Manoa, Makiki, Moanalua watersheds have been urbanized in the early part of the century; therefore, the flood prevention system in these watersheds have been improved over these years. The second task was to evaluate the effect of urbanization upon flood hydrographs from selected watersheds in Oahu. In general, the effect of progress of urbanization on a watershed is evident in the increase in the flood peak and reduction in the time to peak. However, it is felt that this finding cannot be generalized. More hydrological data is needed to substantiate, such a generalization. The third task was to establish the rainfall-runoff data collection devices in the adjoined urban (St. Louis Heights) and natural (Waahila) watersheds. The installation and operation of two auto-recording raingages and two auto-recording water stage recorders were completed. These rainfall and runoff recording instruments will provide the required data for the hydrologic simulation modeling studies and for the evaluation of the effect of urbanization upon watershed hydrology. The fourth task was to initiate the studies of watershed simulation models. Thus far, efforts have been concentrated on two watershed simulation models. one model utilizes an auto-optimal technique in determining the instantaneous unit hydrograph. The other model is a modification of the Kentucky Watershed Model to better fit Hawaiian conditions. Additional modifications are required before a good fit is achieved by both models.


Technical Report No. 65
TRITIUM MEASUREMENT OF NATURAL WATERS ON OAHU, HAWAII: A PRELIMINARY INTERPRETATION (SAMPLING PERIOD: JULY 1969 TO JUNE 1970)

L. Stephen Lau, Theodorus H. Hufen
May 1973

ABSTRACT
Water samples collected from various surface and sub-surface sources on the island of Oahu were analyzed for tritium levels. Tritium activity levels in twenty-five monthly rainwater samples show a seasonal dependence with a maximum in the summer (18.5 to 23 TU) and a minimum in the winter (12 TU). Samples from two surface-water reservoirs had activities of 13.2 and 19.7 TU reflecting contemporary rainwater which is their major source of recharge. Four streams in the Pearl Harbor area showed “rainwater” tritium levels when sampled at high flow. At low flow, two of the streams had low tritium levels indicating ground-water discharge into the stream, while the tritium activity of the other two streams was conparable to rainwater. Tritium activity higher than that of contemporary rainwater (22-38 TU) was exhibited by samples from two springs which discharge perched water, while samples from three wells and two shafts in the Honolulu area showed very little or no tritium activity. Multiple-depth samples obtained from wells in the Pearl Harbor area showed correlations between tritium activities, depths of sampling, and chloride concentrations.


Technical Report No. 66
THE RESPONSE TO TIDAL FLUCTUATIONS OF A LEAKY AQUIFER SYSTEM

John A. Williams, Ta-Chiang Liu
July 1973

ABSTRACT
A system of two isotropic and homogeneous infinite aquifers, which are separated by an aquitard and subject to tidal fluctuations along their coastal boundary, has been analyzed and a mathematical model has been developed for the response of this system to tidal changes. The mathematical model consists of equations for the amplitude and phase of the response of both aquifers to a periodic tide. A computer program using the IBM 360 has been written for the evaluation of these equations. Both the mathematical model and the program have been verified by an electric analog model constructed for that purpose. The mathematical model was evaluated for an aquifer system where both aquifers have the same transmissibility (and therefore the same leakage factor) but where the storage of the upper aquifer was 100 times that of the lower aquifer. Tidal periods of 0.5, 1, and 14 days were used. The results indicate that deviations from a response corresponding to the no-leakage case could be from 50 to 100 percent or more for both the amplitude and the phase angle of either aquifer. Also, such deviations were produced by a relatively moderate amount of leakage, i.e., 1/B2 > 0.154 x 10-4 ft-2


Technical Report No. 67
RAINFALL INTENSITY INSTRUMENTS AND MEASUREMENTS

Charles M. Fullerton, David J. Raymond
June 1973

ABSTRACT
Two instruments have been used to measure the rate of rainfall from tropical clouds over the windward coast of the Island of Hawaii. The Workman intensity gauge employs strain gauges to sense the deflection in a movable trough and hence the flow of water down the trough. The Raymond-Wilson gauge, a new instrument developed during this program, measures the electrical resistance of flowing water to determine the rainfall rate. These instruments were deployed in a small scale array of eight gauges to measure space and time variations in high intensity rainfall as showers move across the network. Comparative measurements were made with a standard weighing rain gauge, a tipping bucket rain gauge and the Jardi rate of rainfall gauge. Both the Workman gauge and the Raymond-Wilson gauge are clearly superior to the other instruments, because of their rapid response time and their capacity to measure high intensity showers continuously and automatically. The Raymond-Wilson gauge contains no moving parts and is operationally more suitable than the Workman gauge for deployment in a network of gauges. A sensor which measures the rate of change of atmospheric pressure has also been developed and is being used in the research program. An example of rainfall intensity measured during a 43-day period in October and November, 1972, is presented, along with a preliminary estimate of the in-cloud liquid water content of shallow Hawaiian clouds.


Technical Report No. 68
OPTIMUM DRILLING SITES FOR GROUND-WATER DEVELOPMENT ON THE EAST COAST OF LANAI ISLAND

William M. Adams, Richie D. Huber
July 1973

ABSTRACT
For a proposed reforestation of the canyon country of east Lanai, seedlings will be required. The seedlings could be grown in east Lanai, preventing the stress of transplantation from a different environment, if an adequate source of high-quality water were available. This study was designed to locate such a source; more specifically, to find optimal sites at which to drill for fresh water. Reconnaissance work in the field took place in July 1970. At 176 places along the eastern coastline, shallow observation wells were dug at the high-tide level during low tide. The temperature and salinity of the ground water there were measured. In most of the canyon gulches, electrical resistivity soundings of the Schlumberger configuration were made. Through analysis of the field data two sectors were identified on the eastern coast: the northern sector, from Federation Village to Lopa, and the southern sector, from Lopa to Naha. Evidence points to the southern sector as being the most promising region for drilling, and specific sites are suggested. However, while the southern sector is superior for the accumulation of ground water, its beach rock is more impermeable than that of the northern sector; hence the southern sector provides less favorable conditions for recharge of the water table. Thus, the southern sector should be developed if a relatively small amount of high-quality ground water is desired from many holes closely spaced along a line–as for the irrigation of seedlings. Should a relatively larger amount of lower quality ground water be preferred, exploitation of the northern sector would be appropriate.