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Unedited Report WRRC-2007-02
Sept. 2005
ABSTRACT - coming soon
Unedited Report WRRC-2007-01
2007
ABSTRACT - coming soon
Unedited Report WRRC-2006-04
2006 ABSTRACT - coming soon
Unedited Report WRRC-2006-03
ABSTRACT - coming soon
Unedited Report WRRC-2006-02
2006
ABSTRACT - coming soon
WRRC-2006-01
2006
ABSTRACT - coming soon
Unedited Report WRRC-2005-06
2005
ABSTRACT - coming soon
WRRC-2005-05 2005
ABSTRACT - coming soon
Unedited Report WRRC-2005-04 2005
ABSTRACT - coming soon
Unedited Report WRRC-2005-03 2005
ABSTRACT - coming soon
WRRC-2005-01
2005
ABSTRACT - coming soon
Unedited Report WRRC-2005-02 2005 ABSTRACT - coming soon
Unedited Report WRRC-2004-03 July 2004
ABSTRACT
The Water Resources Research Center, University of Hawai'i was given a grant
to assist the operating personnel at the Schofield Barracks Wastewater Treatment
Plant in improving the process control for the biological system to improve
the effluent water bacteriological quality. The operating personnel were included
in all process concepts that were used throughout the grant period. These included
going from Phase I conventional process control to Phase II low DO process modification
control to Phase III pseudo-anoxic selector process control. With each process
modification and control change the effluent water quality kept improving to
the point that the State of Hawai'i, Department of Health closed out their Consent
Order Docket Number 92-WW-EO-4 for the Schofield Barracks Wastewater Treatment
Plant. This accomplishment was due to the concerted and diligent efforts of
the operating personnel at the facility.
Unedited Report WRRC-2004-02 May 2004
ABSTRACT
The Department of Environmental Services (ENV), City and County of Honolulu
need to upgrade its sludge treatment system at the Sand Island Wastewater Reclamation
Treatment Facility (SIWRF). ENV selected the Synagro System as the new treatment
to treat sludge at SIWRF because the Synagro System is approved under EPA Part
503 Biosolids Rule to produce a Class A biosolid product. Moreover, since the
biosolid product is dried and pelletized, problems related to vector attraction,
re-growth of sewage pathogens in biosolid, as well as safety issues related
to storage, transporting and application of biosolid to land are minimized.
However, due to concerns related to the reliability and applicability of the
Synagro System to Hawaii, the City Council passed Resolution No.03-193, FD1,
which conditionally approved ENV's application to use the Synagro System. The
approval was conditioned on completing some testing of the Synagro pellets,
and these pellets applied to a Hawaiian soil, for a sewage pathogen (Salmonella).
This Resolution directed Roger S. Fujioka of the University of Hawaii to develop
the appropriate test protocol, to complete the testing and to submit a final
report. Based on the guidelines of the Resolution, two goals of the study were
formulated and the study protocol devised to address these two goals.
Unedited Report WRRC-2004-01 March 2004
ABSTRACT
Central Air-Conditioning Systems (CACS) to cool rooms for most large buildings
such as hotels is a basic necessity. However, since heat is a by-product of
producing cooled air, the CACS is comprised of two units. The first unit is
the chiller-condenser unit, which produces cooled air by extracting heat using
heat exchangers. The second unit is the cooling tower, which uses water to absorb
excess heat from the heat exchangers and to transfer this heated water to the
top of a tower where the heated water is dropped and dispersed as smaller droplets
of water to flow over fills, which represent large surface area. As the water
falls, heat is dissipated to the atmosphere and evaporation of water is a major
factor in cooling of the water. Thus the water collected in a reservoir or sump
at the bottom of the tower is now cool enough to again be re-circulated to absorb
heat from the heat exchangers. However, before the water in the sump can be
pumped to the chiller-condenser unit, the quantity and quality of that water
must be adjusted and improved. The quantity of water must be restored because
of volume loss due to evaporation. The quality of the water must be improved
because the cooling tower is exposed to airborne contaminants, birds, animals,
insects as well as a variety of microorganisms, which may grow on parts of the
tower. These sources add contaminants to the water in the sump and due to evaporation,
the concentration of contaminants increases in the sump water. As a result,
good management of the operation of cooling towers is essential to maintaining
proper functioning of CACS. This includes adding sufficient water (make-up)
of good quality, and discharging some water (blowdown) to reduce the concentrations
of contaminants in the sump water. Another necessary management procedure is
the need to disinfect the sump water because conditions in the sump are ideal
for growth of microorganisms. The concentrations of microorganisms in the sump
water must be controlled because they cause biofilm formation within the chiller-condenser
piping system, which can reduce the efficiency of heat exchangers. Historically,
concentrated forms of chlorine have been used to disinfect cooling tower water.
However, the hazards associated with transport, storage and handling of concentrated
forms of chlorine and their toxic effects on the environment have increased
the cost and risk associated with use of concentrated chlorine to disinfect
water. One way to avoid the recognized problems associated with the use of concentrated
forms of chlorine is to produce only the minimum effective dose of chlorine
on site by a process called electrolysis or using a electric current to ionize
sodium chloride in water to produce low but disinfecting levels of chlorine.
This procedure minimizes the health hazards associated with the use of concentrated
chlorine. In this regard, Kilpatrick Enterprises/Wai Ea Hui Diatomic Systems
have adopted and improved this type of electrolysis method and this process
is called Electrocel Technology System (ETS). This system uses a refined or
high purity form of sodium chloride to produce higher purity chlorine or hypochlorous
acid as the primary disinfecting chemical and limits the formation of other
toxic chemicals. This system has been installed at over 20 sites in the state
of Hawaii, some for as long as 10 years, and Kilpatrick Enterprises/Wai Ea Hui/Diatomic
Systems have stated that this system is an improvement over the traditional
systems of using concentrated forms of chlorine. However, two obstacles have
been recognized in the slow acceptance of this technology. First, many people
are not yet convinced that the ETS is better because it is a relatively new
system and must overcome the acceptance of existing systems. Secondly, it has
been difficult to convince people about the effectiveness of ETS system because
there has not been an independent study, which has evaluated ETS based on monitoring
the quality of water in that system. To address the identified need for ETS,
Water Resources Research Center (WRRC), an independent research unit of the
of the University of Hawaii, was asked to measure relevant water quality parameters
in cooling towers treated by the ETS. The overall goal of this study was to
conduct a short term (3 month) or preliminary (Phase I study) to obtain basic
water quality data needed to evaluate the performance of ETS as an effective
means of treating cooling tower water. The results of this Phase I study were
to determine if a more extensive study would be required. Rapid tests were used
to monitor the following water quality parameters: 1. Total Dissolved Solids
(TDS). 2. Cation mineral content (calcium, magnesium, sodium, silica, iron).
3. Anion mineral content (chloride, sulfates). 4. pH. 5. Turbidity. 6. Chlorine
residual. 7. Phosphates. 8. Nitrates (nutrient load). 9. Bacterial composition
(fecal coliform, E. coli, total heterotrophic bacteria, total aerobic spores,
total anaerobic spores) 10. ATP assay for bacterial load. 11. UV absorbing compounds
using a specific spectrophotometer (Inspectra). 12. Toxic chemicals in water
using the MicrotoxTM assay system. For this study, the effectiveness of ETS
was based on determining the quality of three water samples (input or make-up
water, output or blowdown water, re-circulating sump water) from the cooling
tower installed at Sheraton Waikiki and Outrigger Islander Hotel because ETS
had been used to treat the water at these two cooling waters for a number of
years. In contrast, cooling tower water at the Outrigger Malia Hotel was being
treated by traditional methods during the first two months of this study and
changed to treatment using ETS during the third month. Testing the cooling tower
at this hotel was used to compare the quality of water being treated by traditional
methods and by ETS. By measuring the selected water quality parameters in cooling
water samples from Sheraton Waikiki and Outrigger Islander Hotels, five specific
objectives were addressed. The first objective was to determine whether the
ETS practice related to adding sufficient make-up water and discharging sufficient
blowdown water was effective in controlling contaminants in the sump water.
The monitoring data show excellent quality of the make-up water and relatively
low concentrations of minerals in the sump and blowdown water. Using EPA guidelines
the ratio of TDS in make-up water and sump water was used to determine that
the cooling tower waters at the two hotels were circulated approximately 2 -4
times and well within the recommended 3 - 7 cycles to prevent heavy build up
contaminants in the sump water. These results indicate that the practice used
by ETS to add sufficient make-up water and to remove sufficient blowdown water
is effectively limiting the concentrations of contaminants in the sump water.
The second objective was to determine whether the concentrations of minerals
in the sump waters are adequate to control scaling in heat exchangers. By comparing
the measured water quality parameters in the sump and blowdown water with recommended
water quality criteria for make-up and sump water, it was concluded that most
of the measured water quality parameters (turbidity, pH, iron, sulfates, TDS,
chlorides, Mg) met sump water criteria or make-up water criteria. Only the levels
of silica (207 - 256 mg/l) did not meet the recommended limit of 150 mg/l for
sump water. It is well known that silica is a component of Oahu's groundwater,
which is the source of potable water used as make-up water. Thus, make-up water
rather than external contamination is the most likely source of silica. Taken
together, these results indicate that the concentrations of minerals in the
cooling water for Sheraton Waikiki and Outrigger Islander Hotels are below the
levels to precipitate out of solution to cause problems related to scaling.
The third objective was to determine whether the ETS disinfection system was
effective in controlling microbial growth in the sump water. Based on detectable
levels of total chlorine (0.32 - 1.08 mg/l) as well as free chlorine (0.21 -
0.85 mg/l) and low concentrations of total heterotrophic bacteria (1.32 - 3.52
x i03 CFU/l00 ml), aerobic and anaerobic bacterial spores (17 - 1.33 x l0~ CFU/100
ml), it was concluded that microbial populations in the sump water at the two
hotels are being effectively controlled by the disinfection system used by ETS.
By limiting the growth of microorganisms in the sump water, the disinfection
system is effectively limiting microbial biofilm formation in the heat exchangers.
The fourth objective was to assess the basic health effects quality of blowdown
water for discharge into the environmental waters such as streams and coastal
waters. However, these environmental waters are regulated by concentrations
of fecal bacteria and by presence of toxic chemicals. Analysis of the blowdown
water from the two hotels revealed only trace level (<1 MPN/100 ml) of total
coliform and undetectable levels (0 MPN/100 ml) of E. coli. These results provide
additional evidence that the disinfection system used by ETS is effective. In
addition, acutely toxic chemicals were not detectable in these blowdown water
samples. Thus, the quality of blowdown water meets the basic health related
water quality requirements and will not likely be a source of basic health related
contaminants if discharged into environmental waters such as storm drains, streams
or coastal waters. The fifth objective was to determine the quality of blowdown
water for possible re-uses such as for crop irrigation, landscape watering,
toilet flushing, general washing and laundry activities. Many of these uses
may be especially appropriate in isolated islands where water supply is limited.
This was accomplished by comparing the quality of blowdown water with guidelines
for irrigation water. In this regard, the concentrations for TDS (696 - 869
mg/l) in the blowdown water samples are slightly above the TDS concentrations
(450 - 2000 mg/l) for moderate degree of restriction for irrigation. The concentrations
of sodium (161 - 165 mg/l) in blowdown water slightly exceed the moderate and
severely restricted use of> 100 mg/l for sensitive crops. Similarly the concentrations
of chloride (460 - 486 mg/l) in blowdown water exceed the severely restricted
use of >350 mg/I for sensitive crops. It should be noted that the restricted
use is based on salt sensitive crops and there are other crops that can tolerate
these levels of sodium and chloride. One obvious solution is to dilute the blowdown
water with other sources of waters to reduce the TDS, sodium and chloride concentrations.
Another solution is to select crops or plants, which can tolerate these levels
of TDS, sodium and chloride. Other options include use of blowdown water as
facility washwater before discharge into sewer or to treat the blowdown water
so it can be as make-up water. The sixth objective was to compare the quality
of a traditionally treated cooling tower with that of an ETS treated cooling
water. This was done by analyzing the water quality of cooling tower from Outrigger
Malia Hotel during the last two months it was treated using traditional concentrated
chlorine method with the water quality during the first month this cooling tower
was treated using ETS. A comparison of water quality parameters measured in
the cooling water before and after ETS indicate that most mineral content were
similar before and after ETS. However, monitoring data suggested that the ETS
had not yet stabilized. The concentrations of sodium and chloride in the sump
and blowdown increased after ETS was used. This most likely reflects the use
of sodium chloride by ETS. The concentrations of total heterotrophic bacteria
as well as total coliform and E. co/l were generally lower after the ETS was
employed indicating an improvement in microbial water quality. Thus although
the data was limited, the results indicate that cooling towers which switch
to ETS management can expect an improvement in the quality of cooling tower
water. This study represents the first assessment of the ETS to manage and treat
cooling towers based on measuring selected water quality parameters in the make-up,
sump and blowdown water. An assessment of all of water quality monitoring data
support the conclusion that ETS disinfection system and management procedures
are effective in maintaining good water quality. Maintaining good water quality
is a prerequisite to preventing problems such as scaling and loss of efficiency
of heat exchangers. It also provides for some options on how the blowdown or
wastewater from the ETS may be used. The actual costs, safety performance and
operational effectiveness by the operators of ETS were not part of this assessment.
Unedited Report WRRC-2003-01 October 2003
ABSTRACT
The cost of upgrading the Sand Island Wastewater Treatment Plant to provide
secondary treatment has been estimated at $448 million, doled out over a period
of several years. Such a project involves two opposite economic effects: stimulation
as the builders pay labor and buy materials, and contraction as consumers divert
money from other goods or services to pay for it. Moreover, the initial burst
of spending will cause industries with no direct connection to the project to
experience an increase or decrease in their business, causing subsequent ripples
throughout the economy. With a truly large project, such as the roughly $448
million plant upgrade, these direct and indirect impacts can have serious repercussions
on the entire local economy.
Stimulation and contraction can wield their impacts in different ways, depending
on the type of resources purchased and their interconnections with other sectors
of the economy. Clearly, the stimulative effect of the construction process
impacts on very different industries than would an equal stimulus from, say,
a rise in consumer spending on automobiles. This paper provides estimates of
both positive and negative impacts of a secondary treatment project.
Input-output models provide a convenient, if in some ways imperfect, means
of obtaining these estimates. Hawaii's IO model is produced by the state Department
of Business, Economic Development and Tourism. IO models trace the sales of
each product to other producing sectors (interindustry sales) as well as to
final purchasers (households, investment, exports and government spending).
Thus when a final demand sector, such as government, increases its spending,
the effects can be traced throughout the model's interindustry structure, illuminating
the indirect effects consequent on a given initial burst of spending.
Details of the estimation procedure are outlined in the following sections
of this paper. By way of summary of the estimates, suppose first that the secondary
treatment project is constructed as part of the "State and Local Government
Construction" sector of final demand and that operation and maintenance costs
are paid through higher household spending in fees to the "water and sewer"
industry.
Construction of the plant will cost about $448 million, over a period of some
eight years, with a discounted present value of $363 million. Operation and
maintenance are estimated to cost $9 million per year throughout the assumed
50-year life of the plant, beginning eight years after the project is approved.
This stream of costs has a discounted present value of $186 million. The 10
model estimates that the expenditure of $549 ( $363 + $186) million on plant
construction, operation and maintenance generates additional output (indirect
impacts) of $449 million, for a total of $988 million additional output over
the 50-year life of the treatment plant.
At the same time, the extra sewer fees necessary to pay for construction, operation
and maintenance of the facility will require a withdrawal of the same $549 million
from other economic activities. This diversion, according to the IO model, will
decrease output by $784 million once the indirect, as well as direct, impacts
are accounted for. With these assumptions, the net impact of the investment
is a positive $988 million - $784 million = $203 million.
Of course, sewer fees are only one means of underwriting the investment. If
funded by decreases in other "State and Local Government Consumption," the IO
model indicates a negative impact of $976 million in output, leaving a net positive
impact of only $988 million -$976 million = $12 million. Similarly, various
combinations of withdrawals through households and government are possible.
For example, if 50% of the costs are underwritten by higher sewer fees and 50%
absorbed by decreasing other State and Local Government Consumption, the net
impact on output is a positive $119 million.
Similar estimates are given below for earnings and employment effects. In general,
the net impacts on earnings and employment have more of a tendency to be negative
than do those on output. Assuming the costs are financed entirely through higher
sewer fees, estimated net impacts range from -$164 million to +$203 million
in output, -$244 million to +$91 million in earnings and -8403 to +530 in jobs.
Unedited Report WRRC-2003-02 October 2003
ABSTRACT
This three-phase study is aimed at assessing the status of the Nawiliwili
Watershed on Kaua'i, Hawai'i, and developing a plan for its future protection.
Phase 1 is concerned with validating and documenting existing environmental
data. Phase 2 is aimed at identifying current sources of pollution and contamination
in the watershed. Finally, Phase 3 deals with developing a restoration and protection
plan for the watershed. This report documents the findings for the second phase
of the project. Data collected in this phase were used to determine point and
nonpoint-source contributions as well as to determine whether the water within
the watershed meets water quality standards or if it represents a health hazard.
Hydrological models were also developed toward assessing contributions of point
and nonpoint sources in the watershed. To achieve the study objectives, ten
primary sites and four alternate sites were chosen for sampling. Water quality
parameters measured were turbidity, salinity, temperature, nitrate and phosphate,
and fecal indicator bacteria. The results showed a significant correlation between
turbidity and phosphate concentration in open waters, indicating that sediment
is the main avenue for phosphate contamination. Phosphate is adsorbed by soils
and is carried to stream and ocean waters as particulate bound. In contrast,
the negative correlation between turbidity and nitrate concentration showed
that sediment is not a significant avenue for nitrate contamination. Nitrate
is introduced to streams and the ocean in a dissolved form by means of surface
and subsurface water flows. High turbidity seems to be triggered when the daily
rainfall rate ranges from 2 to 3 inches. The high sediment load after the major
storm of May 13, 2002 demonstrated the vulnerability of the watershed to rainfall
in terms of sediment loads and hence the urgent need for developing strategies
to reduce such loads from various sources. Assessment of turbidity data indicated
that five often sites have a 60% probability for turbidity to be at or to exceed
the standard of 5 NTU. The Papakölea Stream site has the highest sediment level,
with the Nawiliwili Stream site second. These results emphasize the significance
of sediment load originating from agricultural lands that feed the two sites.
The ten primary sites have an 80% probability for phosphate concentrations to
be at or to exceed the suggested level of 0.01 mg/l. The Marriott Culvert and
Pine Trees sites are the two highest in phosphate contamination. In addition,
seven of these ten sites have an 80% probability for nitrate concentrations
to be at or to exceed the suggested level of 0.1 mg/l. The Nawiliwili and Marriott
Culvert sites have the highest nitrate contamination potential. The model HEC-1
was used for estimating flow hydrographs for streams in the Nawiliwili Watershed.
Lack of appropriate data for calibration limited our effort in constructing
a comprehensive model. However, the model can be improved as more information
becomes available. The hydiograph data estimated were used to estimate order
of magnitude nutrient loads to streams and to Nawiliwili Bay. The groundwater
model MODFLOW was used in modeling water flow in the South Lihu'e area, while
the model MT3DMS was used in modeling the transport of a nitrate, which is treated
as conservative dissolved chemical. The modeling package Groundwater Modeling
System (GMS) was used as the working environment for MODFLOW and MT3DMS. The
models provided estimates for the total nitrate loads to the rivers and streams
in the South Lihu'e area. Among the streams in the Nawiliwili area, Hulë'ia
Stream received the largest amount, about 28 kg/year. Other streams in the area
received negligible chemical loads. The estimated values are most likely higher
than the actual values, since our simulations overestimated the concentrations
in the aquifer. It can thus be safely assumed that most of the contaminants
reaching open waters are carried by surface water. The study estimated nutrient
and sediment loads to the streams and Nawiliwili Bay from surface water. For
nitrate, Nawiliwili Stream had the highest load, followed by Puali and Papakölea
Streams. The nitrate load per acre was highest at Puali Stream, followed by
Nawiliwili Stream. The Hulë'ia Stream and Nawiliwili Stream sites received the
highest loads of phosphate, but the Nawiiiwili site alone ranked highest in
terms of phosphate load per unit acre. Loads to Nawiliwili Bay were estimated
on the order of 6 and 2 tons/year for nitrate and phosphate, respectively. The
load estimates provided in this study should be used as a guide only, due to
a number of limitations, including the lack of hydrograph data for calibration.
The results can still be useful, for example, in assessing the relative success
of strategies aimed at reducing nutrient loss to streams and Nawiliwili Bay.
We recommend elaborate hydrologic studies, based on rainfall storms, be conducted
to estimate stream hydrographs at various sampling sites. The concurrent total
maximum daily load studies can be useful in this regard. The Universal Soil
Loss Equation (USLE) was used to estimate the potential sediment loads from
the Nawiliwili Watershed. The estimations were made for three sub-basins of
the Nawiliwili Watershed: Hulë'ia, Puali, and Nawiliwili. We concluded that
the USLE is a useful tool in predicting longtime average (annual) soil losses
due to runoff for certain land uses. The results of the application of the USLE
to the Nawiliwili Watershed yielded a rough estimate of the sediment loads into
Nawiliwili Bay. More accurate predictions can be achieved by using a modified
USLE, along with a geographic information system (GIS) which provides digital
elevation maps and other relevant information. We will further revise the estimates
provided here as we collect more information needed for other approaches. The
results for fecal contamination seem to agree with those previously obtained
for O'ahu, namely, sources of fecal bacteria are environmental in nature. Overland
and subsurface flows wash the fecal bacteria from the soil into streams. It
seems thus that it is not possible to reduce levels of bacteria through management
decisions. Moreover, we have concluded that the concentrations of fecal indicator
bacteria are not related to health risks from sewage contamination. The U.S.
Environmental Protection Agency's (USEPA) standards for assessing water quality
based on concentrations of fecal coliforms and enterococci were exceeded for
most sites studied. Thus, more reliable fecal indicators such as C. perfringens
and FRNA coliphages are needed. However, more studies are needed to verify the
use of these two indicators. Nearly all of the sampling sites contained low
numbers of C. perfringens, indicating that streams in the Nawiliwili Watershed
are not being directly contaminated with sewage discharge. The only exception
was the Pine Trees site, where the recommended standard of 50 CFU C. perfringens/100
ml was exceeded. Papakölea Stream in the Nawiliwili Watershed had the highest
concentration of FRNA coliphages and this was taken as evidence of cesspool
contamination. Since some water samples from Nawiliwili, Papalinahoa, and Puali
Streams contained elevated levels of FRNA coliphages and low levels of C. perfringens,
we concluded that these streams are being occasionally contaminated with cesspool
wastes. The results of this study suggest that environmental sources of fecal
coliform, which are present in soil, may be sources of somatic coliphages. However,
additional studies are recommended to confirm this conclusion. In addition,
genotyping FRNA coliphages to determine human from animal sources can provide
another tool to assess the sources of contamination.
Unedited Report WRRC-2002-02 October 2002
ABSTRACT
This report documents the findings for Phase I of a three-phase study that
is aimed at assessing the status of the Nawiliwili Watershed on Kaua'i and developing
a plan for its future protection. The objectives of this phase include utilizing
sources of existing information to assess current land use in the area and identifying
sources and levels of pollutants believed to be present in the watershed based
on past studies relevant to the project area. Sources of information included
available documents, persons who are familiar with the area, and questionnaires
mailed to concerned individuals. Letters mailed to landowners and operators
in the watershed area asked for their input. Information was also obtained at
community meetings. The study also benefited from a local advisory committee
that included government individuals and environmental groups. Data concurrently
collected by the Nawiliwili Bay Watershed Council are also used here. The study
concluded that little hard scientific data exist for the Nawiliwili Watershed,
especially baseline data. The Hawai'i Department of Health's current Total Maximum
Daily Load (TDML) studies may provide public information that could be useful
in assessing the health of the watershed. Since more baseline data are being
made available, there is a chance to systemically define changes and trends
in the watershed. The study identified sediment, nutrient, and bacterial-contamination
problems in the Nawiliwili watershed and bay. Sediment sources include agricultural
lands, constructioni sites, channel alteration, stream erosion, a quarry, and
urban runoff. Nutrients originate from agriculture practices, golf courses,
cesspools, urban runoff, and wastewater spills. Bacterial contamination originates
from ;, frosted areas, urban runoff, and wastewater treatment spills. Bacterial
contamination originates from cesspools, urban runoff, and wastewater spills.
There is, however, a chance that chemicals from other sources are also present.
The absence of data has created great uncertainties regarding quantification
and assessment of such contaminants. Only the levels of bacterial contamination
are defined based on available measurements. Additional studies are needed to
assess the existence of other chemicals in the watershed and their respective
concentrations. There is also a need to assess the various sources of bacterial
contamination to define the contribution of each. A fairly extensive list of
potential sources of pollution has been identified which can provide a base
for choosing sites for data collection and for sampling-scheme design. There
is a need for new data to confirm these findings. The study used data from the
state of Hawai 'i's GIS web site to identify relevant geographic information
system maps of the area. There is a need, however, to update land-use information,
which has changed in recent years. Finally, there is a need to increase or improve
on the availability of public and private information about the watershed and
to maintain strong ties and full cooperation between environmental groups and
landowners/operators. With availability of .information and full cooperation
of all parties involved, a better understanding of the various processes will
be gained. Developing sound approaches to remediate and protect the watershed
is a goal that should be easy to reach. Scientific research can provide methods
and approaches to maximize economic benefits from the watershed without negatively
affecting the environmental quality.
Unedited Report WRRC-2001-02 December 2001
ABSTRACT
This study set out to evaluate the biological, chemical and agronomic effects
of reclaimed water for irrigation on two golf courses (KGC and LGC) located
over a potable aquifer in Central Oahu. Percolate water and grass samples were
collected on two soils at background sites (potable water irrigation) and pilot-scale
test plots (reclaimed water irrigation) at both golf courses with different
managements during the two-year pilot-scale study. The variations in chemical
characteristics of percolate samples and the relationships of these changes
to soil characteristics (pH, CEC, clay content, etc) and the golf course managements
were determined in a general way based on the results of this study. Great differences in soil water content were observed between the soil at LGC
(wet) and the soil at KGC (dry), and between the two years of the pilot-test.
Fecal coliform was measured in grass and percolate samples. However, whether
or not fecal contamination will be caused due to reclaimed water irrigation
is still in doubt after this study. Significant percolate chloride and sodium
concentration increases were found at the LGC test plot but not at the KGC test
plot. Nitrate leaching was found to mainly relate to fertilization, irrigation
method (amount and schedule), and soil pH. All the percolate samples with nitrate
concentrations higher 20 mg/l were found at background sites with high pH. High
and constant irrigation rates caused a similar degree leaching at the LGC test
plot using reclaimed water as that at the background sites with fertilization
and historic irrigation methods. TDS in percolates is not expected to increase
significantly with the reclaimed water using the irrigation method applied at
the test plots of both golf courses in this study. However, whether or not harmful
agronomic effects will occur cannot be determined in this study without samples
from the dry season and at the soil surface layer. Suction lysimeters are good for monitoring most of chemical parameters measured
and work best at high soil water content, but are not suitable for bacteria
monitoring. Unedited Report WRRC-2001-01 June 2001
ABSTRACT
In situ bioremediation of petroleum hydrocarbon pollutants in aquifers is an
increasingly widespread alternative, or an adjunct, to the costly pump-and-treat
process to decontaminate groundwater and subsurface matrix. The former Grayline
Hawaii baseyard at Honolulu International Airport, the study site, was contaminated
by No. 2 diesel fuel which had been released from underground storage tanks
during tank testing in 1989 and 1991. The product contaminated the groundwater
and the subsurface soil in an area that is under the influence of the tide.
Up to 1.4 ft of free product was found in monitoring wells at the site in 1995.
In a more recent survey (1998) the depth of the free product had decreased to
0.5 cm. This small scale in-situ experiment was undertaken to study the effect
of a bioremediation program on the reduction of the diesel fuel contaminant
concentration and the concomitant changes in microbial populations, and to model
the fate and transport of the product at the Grayline site.
Unedited Report WRRC-2000-03 December 2000
ABSTRACT
Traditional fecal indicator bacteria such as fecal coliform, E. coli and enterococci
have been shown to be unreliable indicators of the hygienic quality of recreational
waters under tropical conditions. One of the major reasons for considering these
bacteria as ineffective indicators of water quality in warm, tropical regions
is that they are consistently found in natural environments (plants, soil, water)
in the absence of any significant contamination of these environments. Since
preliminary studies conducted in Hawaii have indicated soil as the major environmental
source for elevated concentrations of these bacteria in environmental waters,
the aim of this study was to focus on the soil environment to specifically address
two assumptions made by regulatory agencies in using fecal bacteria as indicators
of water quality: first, there should not be an environmental source of these
indicator bacteria unrelated to sewage or fecal matter contamination, and second,
the indicator bacteria do not multiply in the environment. To determine the
validity of these two assumptions under tropical conditions in Hawaii and possibly
other tropical locations, various experiments were conducted. The major findings
are as follows.
I) Analysis of soil samples collected from various locations representing major
soil groups on the island of Oahu showed that fecal indicator bacteria are naturally
found in most of the soil environments, indicating that the fecal bacteria have
adapted to the soil conditions to become part of soil biota. 2) Evidence was
obtained to show that the soil contains adequate nutrients to sustain the populations
of these bacteria. 3) Growth and multiplication of fecal indicator bacteria
in natural soil was dependent on available nutrients (particularly carbon),
moisture and competing microorganisms.
In conclusion, tropical soil conditions are suboptimal for the multiplication
of fecal indicator bacteria. Consequently, these bacteria in natural soil conditions
will probably grow and multiply sporadically when conditions are relatively
optimal. Although concentrations of fecal indicator bacteria in soil represent
only a small fraction of the microbiota, their counts are significant enough
not only to impact the quality of recreational waters but also to nullify two
of the assumptions used in the application of recreational water quality standards.
Thus, there is a need for an alternate and more reliable indicator of water
quality in Hawaii and other tropical locations.
Unedited Report WRRC-2000-02 April 2000
ABSTRACT The State of Hawaii, Department of Health, Wastewater Branch gave
an amendment to the previous grant to the Water Resources Research Center, University
of Hawai'i at Mãnoa for evaluating treated wastewaters (primary, secondary,
and filtered) from various treatment facilities on Oahu for UV disinfection
suitability (Wastewater Characterization at Various Treatment Levels From Oahu
Wastewater Treatment Facilities For UV Disinfection Suitability Phase I: Liquid
Stream Studies). The additional grant funds were used to conduct collimated
beam studies for the same facilities characterized in the previous study.
Sewage or wastewater has traditionally been considered an undesirable product
of society that must be disposed of in the most expeditious way. To protect
the environment and public health, US regulations, require the treatment of
wastewater to remove its organic composition and disinfection to kill its pathogenic
(bacteria, protozoans. and viruses) composition before it can be discharged
into the environment (rivers, lakes, oceans).
Disinfecting wastewater has traditionally been done using chlorine. However,
continued use of chlorine is now being discouraged because chlorine is toxic,
it forms carcinogenic by-products, and it is dangerous to ship, store and handle.
As a result, other disinfectants which do not have these problems are currently
being evaluated as alternatives to chlorine. One disinfectant process which
has been used successfully and which does not have the above problems is Ultraviolet
Light (UV). UV's primary advantages include the fact that it is proven to inactivate
all pathogens, its use does not result in the formation of carcinogenic by-products
nor the presence of toxic residue in the treated water. Moreover, UV is generated
on site and therefore avoids the dangers associated with the shipment and storage
of a dangerous disinfectant. UV as a disinfectant reportedly sometimes has disadvantages
related to costs, photoreactivation, interfering factors (turbidity, suspended
solids, absorbing compounds), uncertainties in measuring dose, no residuals
to be measured to monitor effectiveness of a system. UV disinfection has proven
successful and economical in some treatment facilities but not in others.
The major wastewater treatment facilities on O'ahu utilize a variety of treatment
processes to meet their effluent water quality requirements. They also dispose
of their effluent through: 1) ocean outfaIls, 2) injection wells, 3) inland
water bodies, and 4) water reuse (irrigation). When the final effluent must
be disinfected to reduce the risk of water borne diseases and to achieve its
required level of fecal indicator bacteria, a choice must be made as to which
means of disinfection will be used. But one question that must then be answered
is: What is the microbial density upstream of the disinfection process?. This
is important because as the density increases, the dose (chlorine - concentration
(C) and time (t), UV - intensity (I) and time (t)) requirement also increases.
Besides evaluating the secondary effluent from the listed facilities, primary
(PE - where available), and filtered effluent (FE - where available) were likewise
evaluated and disinfected using collimated beam apparatus.
Unedited Report WRRC-2000-01 April 2000
ABSTRACT
See Abstract for report WRRC-2000-02 above.
Unedited Report WRRC-99-09 December 1999
ABSTRACT
The City and County of Honolulu, Department of Environmental Services (DES
- formerly Department of Wastewater Management) contracted Brown and Caldwell
to conduct a Preliminary Engineering Report (PER) to determine which disinfectant
(chlorine or ultraviolet radiation - UV) would be most appropriate for the effluent
(primary only) from the Sand Island Wastewater Treatment Plant (Sand Island
WWTP) prior to discharge through its deep ocean outfall. As part of this PER,
the University of Hawai'i at Mànoa, Water Resources Research Center (WRRC) was
retained to conduct primary effluent characterization using physical and microbial
parameters previously determined to affect UV treatment of wastewater and disinfection
testing (chlorine - jar test, UV - collimated beam) to provide sufficient data
for deciding an appropriate disinfection method and system.
As population and greater demands for water supply and recreational water uses
have increased over the last 30 years, so has the risk of human exposure to
wastewaters discharged into the environment. Dilution, time and distance (natural
safeguards) before contact or use, can no longer be depended on in the same
ways because there are more dischargers and larger wastewater volumes being
discharged than ever before. Human pathogens are excreted by infected individuals
into domestic wastewaters. Even after undergoing treatment the effluent from
these facilities can still contaminate potable water supplies, recreational
waters, and shellfish growing areas with pathogens. When the possibility for
human exposure to wastewater contaminated environmental waters exist, the microbes
of concern are enteric bacteria, viruses, and protozoa. Diseases spread by these
pathogen groups via consumption (water or aquatic life) and/or contact can be
severe and sometimes crippling (EPA 1986).
Disinfection is necessary to minimize infectious disease transmission when
there may be human contact. Along this line of thought, the Environmental Protection
Agency (EPA) adopted a policy that essentially states (EPA 1986):
Unedited Report WRRC-99-08 December 1999
ABSTRACT The availability of safe drinking water for every person on this earth
continues to be one of the most urgent humanitarian needs today. This situation
is especially apparent in developing countries where more than 1 billion people
still do not receive a continuous supply of clean, safe water piped directly
into their home (1). Under these conditions, people must rely on any feasible
means to obtain drinking and household water, ranging from the use of streams,
ponds, wells, lakes, or rivers to the use of roofs to collect rainwater. These
sources of water are usually contaminated but for many people there are no feasible
or affordable means to treat or disinfect the water. The use of unprotected
and untreated drinking water is a major reason for the approximately nine hundred
million cases of diarrheal diseases reported each year (2). Many of these populations
live in remote areas where electrical power and modern technology for water
disinfection are not available. For these populations there is a need for a
simple, low-cost, and sustainable technology for water disinfection.
Solar radiation is a sustainable energy source which is present throughout
the world and is more abundant in the tropical areas of the world, where most
of the people who lack safe drinking water live. To take advantage of this natural
source of energy, several companies have developed solar pasteurization units,
which use sunlight to heat water and use the well known principle of high heat
"pasteurization" to disinfect pathogens in the water. The process of water pasteurization
is to heat water to >60°C for 30 minutes. This is a proven approach to disinfect
pathogens present in clear as well as turbid water. The two major limitations
of solar pasteurization units are the relative small volumes of water which
can be disinfected per unit and the reliability of the system in achieving the
necessary temperature and dwell time to disinfect the water. In Honolulu, solar
pasteurization units were developed to disinfect water for individual families
by Mr. Grandinetti of Grand Solar Inc. Our laboratory previously evaluated a
prototype system for this unit and determined that the unit could effectively
disinfect various sources of water under normal sunlight conditions in Hawaii.
Our final evaluative report describes the treatment effectiveness of the Grand
Solar Water Heater systems in disinfecting all the relevant groups of health
related microorganisms in water (3). These units are now being sold primarily
outside the US in countries such as El Salvador, Guatemala, India, Philippines,
Malaysia and Tanzania by Safe Water Systems. The advantage of this system is
that it requires few moving components, no electricity and therefore simplifies
the operation and maintenance of this water disinfection unit.
Safe Water Systems is currently selling a solar powered water disinfection
system called the Family SolSaver. This unit was designed to use durable, lightweight
and ultraviolet-resistant materials to maximize the capture of the heat-producing
rays of sunlight and to retain the heat within the unit This solar pasteurization
unit works well during sustained sunny days but cannot be relied upon during
cloudy days when sunlight is limited and the necessary pasteurization temperatures
cannot be achieved. In summary, the current design of the Family SolSaver uses
the radiation of sunlight to heat the water. However, several studies (4,5,6,7,8)
have reported that some wavelengths of sunlight will directly inactivate microorganisms
in a mechanism separate from elevated temperature or the well described pasteurization
mechanism. Based on this new information, it is theoretically possible to devise
a solar disinfecting unit which uses the two independent mechanisms of sunlight
(heat, direct radiation) to improve its disinfecting capacity. To address this
possibility Mr. John Grandinetti has modified the design of his Family SolSaver
for experimental evaluation. The first modification was to use sunlight reflectors
to increase the available amount of sunlight to heat the water. The second modification
was to use an UV transmittable plastic cover sheet rather than an UV resistant
material to enable more wavelengths of sunlight to enter and treat the water
by direct irradiation. The identified need was to field test the modified designs
of the Family SolSaver systems unit and to obtain scientific data to quantify
the effectiveness of these experimental designs.
Unedited Report WRRC-99-07 December 1999
ABSTRACT
The Honolulu Board of Water Supply (BWS) operates granular-activated carbon
(GAC) contactors to remove TCP, EDB, and DBCP from well water in central Oahu.
These contactors first became operational in 1986. Numerous additional contactors
are currently either under construction or in the planning stage. Currently
the spent GAC is being disposed of at a local landfill and replaced with virgin
GAC at an annual cost of nearly $500,000. A novel chemical regeneration technique
has been developed which may reduce these costs by more than 50%. A literature
and industry search was conducted into current and emerging regeneration techniques
and local disposal alternatives. The result of that effort was to recommend
bench-scale followed by pilot-scale chemical regeneration studies.
Bench-scale studies were conducted using rapid small-scale column tests (RSSCT)
to determine the best regeneration scheme for dibromoethane (EDB), thchloropropane
(TCP), and dibromochioropropane (DBCP) removal from the spent GAC. Short-term
studies using BWS's spent GAC found that many combinations of either an acid
or a base and a solvent could desorb all of the pesticides as long as the solvents
were used at 100% strength. Side-by-side RSSCTs using Mililani well water and
spiked deionized water found that natural organic matter (NOM) competes with
the pesticides and reduces GAC adsorption capacity by 30% for DBCP and 49% for
TCP. Preliminary RSSCTs using Mililani well water to load the columns found
that acetone alone was not an effective regenerant. Long-term RSSCTs are being
conducted using Mililani well water. The columns treat the well water until
pesticide breakthrough and then are regenerated. After regeneration, they again
treat the well water. This has been repeated seven times so far. The use of
either an acid or a base plus acetone was effective for 5 load/regeneration
cycles. After the fifth cycle the regeneration protocol was modified to include
the use of both an acid and a base and acetone. This later protocol seems able
to regenerate the GAC to its virgin adsorption capacity. It is not yet clear
how many cycles are possible. This indicates that it is technically feasible
to chemically regenerate BWS's GAC such that it can be reused repeatedly and
indefinitely. The bench-scale experiments have been very successful and were
able to demonstrate that the solvent (acetone) can be reused. Preliminary investigations
have been conducted into waste disposal processes including recovery of acetone
(via distillation), neutralization of acid/base with disposal to the wastewater
system, and chemical destruction of desorbed pesticides followed by disposal
to the wastewater system.
Unedited Report WRRC-99-06 September 2000
ABSTRACT
Unedited Report WRRC-99-05 February 1999
ABSTRACT
Unedited Report WRRC-99-04 January 1999
ABSTRACT Chemical regeneration is one method of regenerating spent granular
activated carbon. The chemicals being considered for use are acetic acid, acetone,
formic acid, hydrochloric acid, sodium hydroxide, methanol, ethanol, and 2-Propanol.
The potential environmental and public health effects of chemical regeneration
of spent granular activated carbon causes concern. Information on the eight
chemicals and environmental regulations were gathered by doing a literature
survey. An evaluation of these chemicals- occupational standards; acute and
chronic effects; carcinogenic, reproductive, and mutagenic effects; and environmental
fate- showed no anticipated hazards. With the proper preventative and mitigative
measures, any unnecessary exposure and adverse effects can be prevented. Chemical
regeneration is an alternative to handling spent GAC.
Unedited Report WRRC-99-03 October 1999
ABSTRACT
The OESIS-750 individual wastewater treatment unit was delivered to the Sand
Island Wastewater Treatment Plant (SIWWTP). A pump, plumbing, electronic valves,
a dosing tank with float switch, and a programmable logic controller (the "system")
were fitted to the OESIS-750. The system draws screened raw wastewater from
the SIWWTP influent channel as influent and treated effluent is discharged into
the same channel. The system was designed to provide a total flow of 400 gal/day
to the OESIS-750 in a manner prescribed by the National Sanitation Foundation
(NSF) Standard 40 test protocol. The NSF Standard 40 protocol calls for 35%
of the daily flow to enter between 6 am and 9 am, 25% to enter between 11 am
and 2 pm, and 40% to enter between 5 pm and 8 pm. The NSF Standard 40 calls
for a six-month continuous standard performance period followed by a series
of four stress tests.
The OESIS-750 individual wastewater treatment unit was brought on-line for
continuous operation on September 21, 1998. The six-month standard performance
period was completed on March 26, 1999. Programmable samplers (ISCO 3700) were
utilized to collect influent and effluent samples five-days-per-week during
the period when the unit received influent. Effluent samples were composited
in proportion to the influent flow pattern. Influent and effluent samples were
monitored for biochemical oxygen demand (BOD5), suspended solids (SS), and volatile
suspended solids (VSS). In addition, the dissolved oxygen (DO), temperature,
and pH within the aeration tank portion of the system have been measured five-days-per-week.
During the six-month standard performance period, the OESIS-750 unit performed
very well. Minimum performance for production of a NSF Standard 40 Class I effluent
requires that the 30-consecutive-day mean effluent concentration of BOD5 and
SS be no greater than 30 mg/L and that there be at least 85% total removal.
At the same time, the mean values of BOD5 and SS for any 7-consecutive days
cannot be greater than 45 mg/liter. In addition, the effluent pH must always
be between the limits of 6.0 and 9.0. During this period, effluent BOD5 averaged
13.9 mg/L, and effluent TSS averaged 13.1 mg/L. The data indicate that the OESIS-750
easily met the requirements for a NSF Standard 40 Class I effluent.
A series of four stress tests specified by the NSF protocol were conducted
between May 25 and July 17, 1999. The OESIS-750 unit performed well during the
series of four stress tests. As expected, the some of the stress tests had a
significant effect on the treatment performance (particularly effluent BOD).
However, these observed effects were short-lived and the system recovered quickly
to typical long-term performance within 3-4 days following the return of normal
flows.
Unedited Report WRRC-99-02 Hisato 'Keith' Oshiro and Roger W. Babcock, Jr.
ABSTRACT
This thesis summarizes the activities of the Moloka'i Fishpond Restoration
Water Quality Study conducted by the Water Resources Research Center (WRRC)
at the University of Hawai'i at Manoa.
EPA-approved methods were utilized to analyze Moloka'i fishpond water samples
and the data were compared with DOH criteria. The fishponds nearly always met
the DOH water quality criteria for pH, dissolved oxygen, temperature, and salinity.
Due to inadequate detection limits in the methods used, it cannot be determined
whether ammonia nitrogen, nitrate/nitrite nitrogen, and chlorophyll-a meet the
criteria. The criteria for total nitrogen, total phosphorus, turbidity, dissolved
oxygen, temperature, and salinity may have to be modified because they apparently
are not achievable under natural/pristine conditions in the vicinity of the
flshponds. There are no criteria for orthophosphorus, total suspended solids,
and volatile suspended solids.
The simplified, ready-to-use Hach methods for total nitrogen, nitrate nitrogen,
nitrite nitrogen, total phosphorus, and orthophosphorus were compared to EPA-approved
methods. The Hach total phosphorus and orthophosphorus methods are EPA-approved
and were found to be statistically equivalent to the standard method for seawater
analysis. The Hach nitrite nitrogen method is EPA-approved, but was found to
be statistically not equivalent to the standard method The Hach total nitrogen
and nitrate nitrogen methods were found to be statistically not equivalent,
maybe due to interference in the samples and different detection ranges between
the methods. The Hach methods can be used to obtain a rough estimate of a parameter
in seawater, usually for on-site analysis.
Unedited Report WRRC-99-01 May 1999
ABSTRACT
Unedited Report WRRC-98-13 June 1998
ABSTRACT
An exploratory study was conducted under Sea Grant Mini-Grant Program to test
the hypothesis that by implementing an innovative monitoring strategy of analyzing
waters for three complementary tests, the combined test results can more reliably
determine whether that environmental water is contaminated with point source
pollution (sewage) or non-point source pollution (stream, storm drain). These
three selected ~tests were used to analyze the quality of water samples obtained
from streams, coastal waters used for swimming as well as shoreline, nearshore
and offshore ocean sites near three of the ocean sewage outfalls (Waianae, Mokapu
and Sand Island) operated by the City and County of Honolulu. The monitoring
strategy involved the use of the following three tests:
1. Viable assay for enterococci bacteria. This is a relatively simple test
and is the only test, which can be used to determine whether the water meets
the EPA water quality standard for swimming based on 35 enterococci/100 ml.
This test was able to enumerate enterococci bacteria primarily in water samples
from coastal waters and in ocean water samples near the sewage ocean outfalls.
However, this assay has three disadvantages. First, the test results take so
long (48 hours) that it is not applicable to address the risk to swimmers using
that water on that given day. Second, the enterococci bacteria are less stable
in marine waters than many sewage-borne pathogens such as viruses and therefore
absence or low levels of enterococci in water samples, may provide a false sense
of security. Third, in Hawaii, there are environmental sources (soil, stream,
storm drain) of enterococci, which are not directly related to sewage contamination,
and therefore the presence of these bacteria in environmental waters may provide
a false sense of risk to swimmers.
2. Enzymatic assay for ATP This test measures total microbial activity and
indirectly the levels of nutrients as a class of pollutant in a given water
sample. Nutrient, as a source of pollution, may be from point or non-point sources
of pollution. Therefore, the test results may be ambiguous by itself, but are
useful when combined with other water quality data. An advantage of this test
is that it can provide results rapidly. Some tests can provide results in minutes
although the test used in this study took approximately 6 hours. Use of this
test can provide results within minutes so conclusions about water quality can
be made quickly and actions can be taken on that same day. The results of this
assay can characterize the quality of water at different marine sites. For example
it can differentiate between coastal sites with high microbial activity (high
nutrient load) and those with low microbial activity (low nutrient load).
3. Gene probe test using polymerase chain reaction (PCR) assay for Bacterioides
fragilis group (BFG) bacteria in water samples. This group of bacteria
is present in human feces and sewage at concentrations approximately 10,000
greater than viable concentrations of enterococci. Since the PCR test detects
both dead and alive bacteria, this is a very sensitive and conservative test
for the presence of sewage in the water. The advantage of this test is its sensitivity.
The disadvantage of this test is that it measures the presence of dead as well
as live microorganisms
Unedited Report WRRC-98-12 May 1998
ABSTRACT
A literature and industry search of GAC regeneration technologies has been
conducted in order to assess the feasibility of implementing various established
and emerging technologies for regeneration of the Board of Water Supply's (BWS's)
spent granular activated carbon (GAC). Both potential on-site methods and off-site
methods were considered. Similarly and concurrently, a literature and industry
search of local disposal options for the spent GAC was also conducted. In addition,
and also concurrently, bench-scale chemical GAC regeneration experiments have
been underway at the University of Hawaii, Water Resources Research Center for
over twelve months under separate sponsorship. Multiple factors were considered
for assessment of alternative regeneration and disposal methods including regeneration
efficiency, cost, degree of development, practicality/ease of Use, environmental/regulatory
issues/permits (emissions, waste residuals), public acceptability, and compatibility
with BWS operations/facilities.
A great deal of literature was found and is summarized in this report The report
is organized beginning with an introduction to the Pearl Harbor Aquifer pesticide
contamination, the GAC contactor columns that are in place, the characteristics
of the spent GAC, and a brief overview of the most common GAC regeneration techniques.
Next, several on-site methods are reviewed (organic and inorganic solvent chemical
regeneration, supercritical fluid regeneration, thermal, biological, photochemical,
and electrochemical) which could be implemented at the existing wellhead sites
either inside the contactors (in situ) or directly adjacent to them (ex situ).
The review includes development of hypothetical system facilities, detailed
examination of numerous feasibility criteria, and generation of operating and
construction cost estimates. Next, two off-site methods are reviewed (construction
of a new local thermal regeneration facility, and use of a mainland-based thermal
regeneration contractor) and similar analyses performed and cost estimates prepared.
Next, three different local disposal options are reviewed (landfilling, incineration,
and reuse as a construction material additive) and similar analyses performed
and cost estimates prepared. Finally, in the last chapter, all of the findings
are summarized and highlighted, overall comparisons are made using a scoring
system to determine the top three alternatives, and recommendations are made
regarding the best path for continuation of this work.
Using a weighted scoring system and a set of 13 criteria, the top three alternatives
were determined to be; 1) use of a mainland-based thermal regeneration contractor,
2) on-site inorganic/organic solvent chemical regeneration, and 3) landfilling.
Based upon annual operating costs alone, the chemical regeneration alternative
is the top choice. The estimated annual costs for the top three alternatives
are $419,700/yr - mainland contractor, $366,100/yr - Iandfilling, and
$59,300/yr - chemical regeneration. It is important to note also that only
one of the top three options has a none-zero capital construction cost (chemical
regeneration - $104,000), however, the capital cost is so low that a new facility
could be constructed every year and BWS could still save money compared to the
other top alternatives. The limitations of the alternatives scoring process
are discussed in the report. The cost estimates for the mainland contractor
and for landfilling are fairly firm, however, estimates for the chemical regeneration
alternative are based upon bench-scale experimental results and large extrapolation
such that they are much less firm. In spite of this it seems justified to say
that research on the chemical regeneration method should continue since high
regeneration efficiencies appear to be highly feasible and there appears to
be potential for a significant annual operating cost savings compared to the
other methods.
Based upon the findings of this literature and industry search, it is recommended
that on-site chemical regeneration methods be further investigated in a step-wise
manner beginning with laboratory minicolumn studies, followed by pilot-scale
trials and finally full-scale trials assuming continued favorable results at
each stage. The additional research efforts should focus on the following areas:
Unedited Report WRRC-98-11 April 1998
ABSTRACT
More than fifty years ago, pesticide use in central Oahu began as Hawaii's
agricultural economy was flourishing. These pesticides were necessary in order
to prevent pests and other parasites from infecting or otherwise harming sugarcane
and pineapple crops. Three of these pesticides (dibromoethane - EDB, trichloropropane
- TCP, and dibromochloropropane - DBCP) caused a great deal of alarm in the
early 1980s when trace amounts of each were identified in the well water supplies
of central Oahu. Their presence rallied the State to find a solution to their
source, containment, and treatment. The pesticide problem posed a unique challenge
to the State and Federal governments since regulatory limits were not established
for them. In 1992, the Hawaii State Department of Health (DOH) established maximum
contaminant levels (MCLs) of 40 mg/L for EDB and DBCP and 800 mg/L for TCP.
In order to treat the contaminated water, the Board of Water Supply (BWS) reviewed
several treatment schemes and chose to use granular-activated carbon (GAC) contactors.
These contactors were designed and installed in Waipahu, Mililani, and Kunia.
To date, all continue to operate and more contactors are being designed for
installment in other areas. The contactors are extremely efficient in removing
the pesticides from the water; however, spent carbon disposal has been a concern.
The BWS has sought to find alternative means to disposal to prolong the carbon's
useful life and minimize operating cost (currently, disposal and replacement
costs are greater than $400,000 per year). It is this problem that is addressed
by the study conducted here. This study incorporates both regeneration and biodegradation
components in order to develop a complete bioregeneration process. The available
literature has described several regeneration options; however, solvent regeneration
was the focus here. Solvents included in this study were acetone and 2-propanol
used in conjunction with hydrochloric, acetic, and formic acids and sodium hydroxide.
Included in the regeneration portion of this study were separate experiments
to determine competition between the pesticides and the natural organic matter
(NOM) that exists in the water. This was a necessary objective in order to see
if the NOM greatly interferes with pesticide adsorption which would cause premature
breakthrough. Biodegradation studies were conducted in batch tests to determine
the extent of biodegradation under aerobic, anoxic, and anaerobic conditions.
Current results have shown that pesticide removal from the spent carbon is
effective using formic acid and acetic acid without additional solvents. Removal
of the pesticides were upwards of 80% using acetic acid and over 95% using formic
acid. However, neither removed more than 25% of the DBCP adsorbed onto the carbon.
Hydrochloric acid removed about 50-70% of each pesticide and sodium hydroxide
removed about 40% of each. When combinations of regenerants were attempted,
these percentages soared. When any of the acids or the base were used with either
acetone or 2-propanol, removal percentages increased to almost 99% for all three
pesticides. Though work in the field of solvent regeneration is not complete,
these data show promise and it is hoped that one combination will be optimized
to provide the practical balance between regeneration efficiency and cost.
From the long-term experiments to determine NOM competition, conclusive results
have been difficult to draw. It seems that NOM is adsorbed, however, interference
or competition for adsorption sites does not seem to have an extremely significant
effect on pesticide breakthrough. There is evidence that NOM was adsorbed and
then later desorbed during experimental filtration runs. When two columns were
operated simultaneously (one with well water and the other with spiked deionized
water containing the pesticides only), the column used to treat the spiked water
did break through after the first, but only 2000 bed volumes after the first
one broke through. It was anticipated that the column would run much longer.
These results seem to show that NOM interference, if any, is not a large problem.
Again, further work is required to study NOM-pesticide competition.
In batch shake-flask tests, several bacterial cultures were tested under aerobic,
anoxic, and anaerobic conditions. These experiments have shown that the pesticides
are biodegradable, but the problem of volatilization has made it difficult to
quantify the extent of biodegradation. Additional work in the biodegradation
area continues to be conducted (with control of volatilization) and more conclusive
data is anticipated in the future. Overall, promising progress has been made
in both the areas of regeneration and biodegradation. On-going studies will
produce additional results that will ultimately be used to develop a full-scale
bioregeneration process for the BWS.
Unedited Report WRRC-98-10 December 1998
ABSTRACT
The New Waikiki Natatorium plans to use an innovative construction design to
use the natural flow of ocean water from the Ewa side of the Natatorium to enter
the pool, to effectively circulate throughout the pool and to transport the
water out of the pool from the Diamond Head end. The objective of this natatorium
design is to have effective and continuous exchanges of water in the pool with
fresh clean ocean water which will ensure that the quality of the water in the
pool will be similar to the quality of the water outside the pool. However,
to accommodate the swimming conditions, the flow of water in the pool will have
to be reduced and by doing so may create conditions in the pool where particles,
nutrients and microorganisms in the water can accumulate. In freshwater pools,
chlorine is used to continuously disinfect the pool water and thereby control
the risk of water borne diseases. Chlorination to disinfect ocean water in the
Natatorium is not feasible and therefore the water in the New Natatorium will
not be disinfected. As a result, concerns have been raised on the possibility
that the concentrations of pathogenic microorganisms in the pool water will
increase to a critical level to cause unacceptable incidences of infections
and diseases among swimmers. Some swimmers using Kaimana Beach have also expressed
their concerns that poor water quality being discharged from the natatorium
pool will contaminate waters in the Kaimana Beach area.
The City and County of Honolulu has stated that good pool water quality at
the New Natatorium will be maintained by the combination of the following four
factors. First, the assumption that the ambient quality of the source of ocean
water entering the pool is good and does not contain elevated levels of water
borne pathogens. This assumption is reasonable because waters in the Waikiki
Beach area have had a long history of meeting existing recreational water quality
standards. Second, the engineering design of the New Natatorium will result
in the effective circulation of water within the pool and constant exchange
of clean ocean water flowing through the pool. Third, a management plan in the
use of the New Natatorium which will prevent water contamination and disease
transmission. Fourth, a water monitoring program to document that the quality
of water in the pool is suitable for swimming.
The goal of this study is to determine the ambient quality (turbidity, concentrations
of health related bacteria) of the ocean water surrounding the existing Waikiki
Natatorium which will be the source and receiving water for the New Waikiki
Natatorium. To achieve this goal the following objectives were pursued.
Unedited Report WRRC-98-09 December 1998
ABSTRACT
Unedited Report WRRC-98-08 December 1998
ABSTRACT
A conceptual model, based upon the bicontinuum double porosity approach, has
been developed to simulate water flow and reactive chemical transport in both
the soil matrix and the macropore region. Flow of water in both regions is governed
by Richards' equation and chemical transport is based upon convective-dispersive
mechanisms with linear kinetic sorption and first-order decay. The pressure-water
content and the pressure-conductivity relationship for the unsaturated soil
in each of the two regions are based upon the van Genuchten-Mualem relationships.
The developed model was in one- and two-space dimensions and it contained several
improvements over the previously proposed one-dimensional conceptual flow and
transport models.
Convergence was a problem when the magnitude of coupling or the size of the
time step was large. Analyses of the magnitudes of the flow and transport parameters
on the prediction of pressure and concentration profiles were presented. These
include fluid and solute mass transfer coefficients, saturated hydraulic conductivity
of the interface through which mass transfer takes place, sorption distribution
coefficient and reaction rate, decay rate, and root extraction of water. From
the pressure and the concentration profiles, it was observed that the fluid
and the solute mass transfer coefficients have the greatest impact on model
predictions. Sorption distribution coefficients and reaction rates appeared
to have moderate impact on concentration profiles. For short durations of simulation
(e.g. minutes to a few hours), decay rates and root uptake of water appeared
to have negligible effect.
The model was used to study the impact of agricultural management practices
such as row versus nonrow crops, conventional versus conservation tillage, organic
amendment, and furrow irrigation on the prediction of pressure and concentration
profiles for a local soil with a given degree of macroporosity. With the chosen
set of parameters, the importance of macropores on the deep movement of water
and chemicals was observed. Once the model parameters for a given soil type
are estimated and the the model is validated, it can effectively be used as
a management tool to evaluate the impact of agricultural management practices.
Unedited Report WRRC-98-07 May 1998
ABSTRACT
Unedited Report WRRC-98-06 October 1998
ABSTRACT
Unedited Report WRRC-98-05 August 1998
ABSTRACT
Unedited Report WRRC-98-04 March 1998
ABSTRACT
Fecal indicator bacteria are found to reproduce in soil in Hawaii's environment. This impacts bacterial water quality
assessment Kailua Regional Wastewater Treatment Plant Disinfection Facility-Pilot Study January 1998
ABSTRACT A pilot study to determine the range of physical and microbiological
characteristics of treated wastewater from the Kailua Regional Wastewater Treatment
Plant and to determine the effectiveness of ultraviolet radiation disinfection
using two different UV lamp technologies.
Unedited Report WRRC-98-02 November 1997
ABSTRACT
Effluents from wastewater, agricultural, animal, and industrial facilities
are commonly discharged into environmental waters (streams, lakes, estuaries,
harbors, ocean). Since these discharges are a potential source for a variety
of water-borne pathogens, there is a public health risk if recreational waters
are contaminated by these discharges. To address this public health risk, USEPA
has developed recreational water quality standards based on culturable concentrations
of fecal indicator bacteria ( fecal coliform, i coil, enterococci). Although
the use of these microbial water quality standards have been useful, these standards
are not always reliable because the fecal bacterial indicators die off' much
more rapidly in environmental waters, especially marine waters, than many fecal
borne pathogens (human enteric viruses, enteric protozoans). As a result the
absence of fecal bacteria in environmental waters may not accurately predict
the absence of sewage-borne pathogens.
In Hawaii, the USEPA recreational water quality standards have been shown to
be inappropriate because the same fecal indicators used to establish water quality
standards are multiplying in the soil environment of Hawaii and is the source
of the naturally high concentrations of these fecal bacteria in all streams,
storm drains and land run-off. In Hawaii, these naturally occurring, environmental
sources of fecal bacteria are not indicative of sewage contamination because
the sources of these bacteria are not from sewage or any other effluent discharge.
Moreover, many sewage-borne pathogens (human enteric viruses, enteric protozoans)
cannot multiply under environmental conditions. As a result, in Hawaii. the
presence of fecal bacteria in environmental waters may not accurately predict
the presence of sewage-borne pathogens.
Based on the limitation of using fecal bacteria indicators, there is a strong
recognition that environmental waters should be monitored for the presence of
pathogens. However, all attempts to monitor environmental waters for sewage-borne
pathogens using traditional, culturable methods have been determined to be unfeasible.
Thus, there is a need to develop newer methods to assess the sanitary quality
of environmental waters based on detection of sewage-borne pathogens. Recent
developments of molecular genetic methods indicate that these newer methods
can overcome many of the limitations of culturable methods. Recognizing the
potential of these new molecular genetic methods, Dr. Carol Palmer of the County
Sanitation Districts of Orange County (CSDOC) , Dr. Mark Sobsey of the University
of North Carolina and Dr. Roger Fujioka of the University of Hawaii collaborated
in writing a joint proposal to the National Water Research Institute (NWRI).
The goal of this joint study was to apply newer molecular genetic methods to
assess coastal water quality in the United States by conducting comparable studies
at coastal sites representing the east coast (North Carolina), the west coast
(California) and the tropical pacific island coasts (Hawaii).
Unedited Report WRRC-98-01 October 1997
ABSTRACT
Report on a microbial water quality monitoring program to determine whether
the Honolulu Board of Water Supply's deep groundwater sources and water in the
potable distribution system may be vulnerable to contamination by fecal matter.
Unedited Report WRRC-97-04 January 1997
ABSTRACT
The objectives of this project are to evaluate operations, make recommendations,
and train personnel at the Schofield Barracks Wastewater Treatment Plant (SBWWTP)
for the purpose of improving the operating efficiency of the plant. There are
several tasks associated with this study, including (1) implementing a process
monitoring program, (2) determining treatment capacities, (3) developing process
control strategies, (4) providing technical guidance, (5) review/update operations
and maintenance manual, and (6) conducting mini-studies.
Like the first two progress reports, this third quarterly progress report contains
a brief summary of the more important findings obtained thus far and descriptions
of in-progress efforts.
Since the second quarterly progress report we have continued to collect and
analyze a large quantity of samples from the treatment plant in order to characterize
all process streams (Task 1). In this report, these data are presented and summary
calculations of treatment efficiency have been prepared for primary clarification,
activated sludge, secondary clarification, dissolved air flotation thickening
(DAFF), anaerobic digestion, and centrifuge dewatering.
In this report, results are presented which indicate that plant influent suspended
solids and oxygen demand have higher average values and are more variable than
national averages, less than optimal performance of the sludge thickener results
in a cyclic transfer of solids between the liquid process stream and the solids
process stream, fulll nitrification is routinely acheived, there remains a bulking
problem in the activated sludge process, the dinisfection process has some problems
meeting its objectives, the primary and secondary processes generally perform
within established norms, the sludge thikening and digestion processes perform
poorly, primary clarifier load splitting is inadequate, aeration basin flow
splitting is probably adequate, secondary clarifier flow splitting is significantly
different than as designed, anoxic selectors can effectively eliminate activated
sludge bulking, and the bioaugmentation products used at the plant may not be
effective.
Up to this point, the focus of our efforts has been on process monitoring for
assessment of process efficiency and determination of needs and operating strategies.
In the fourth quarter we plan to spend more effort on development of process
control strategies and on necessary operation and maintenance manual modifications.
Specific goals for the fourth quarter of this project include:
Unedited Report WRRC-97-03 May 1997
ABSTRACT
Integrating intermittent aeration for the treatment of combined dilute and anaerobic digested swine wastewater in a field swine wastewater treatment
system was investigated. Four operation models in term of ratio of aeration to no-aeration of 60:36, 5:1, 4:2 and 3:3 hour were evaluated. At the HRT of 3.2
days and ratio of aeration to non-aeration of 3:3, the removal efficiency of BOD5, Total-N, TSS and Total-P of 98.0%, 92.4%, 95.6% and 59.4% could
be achieved, respectively. The effluent quality of OD5, N03-N, NH4-N and TSS concentrations were 35 ± 12 mg/l, 2.6 ± 0.8 mg/l, 36 ± 28 mg/l
and 78 ± 13 mg/l, respectively. The operational criteria were developed for integrating the intermittent aeration in the swine wastewater treatment system (including
anaerobic reactors and sedimentation unit).
Economical evaluation of the swine wastewater treatment system integrating the intermittent aeration unit was conducted. It was found that break-even point was the
operation of 166 pigs if the biogas and stabilized sludge were utilized. If the byproducts were not utilized, the cost of the treatment system is $12.30; $7.92, $7.21,
$7.06 and $6.90 for the operation of 300, 1000, 2000, 3000 and 5000 pigs per year, respectively.
Integrating the intermittent aeration unit into the swine waste treatment system provides effective odor control, reduction of energy cost and treated wastewater reuse
without degradation of environmental quality.
Unedited Report WRRC-97-02 1977
ABSTRACT 2
This project was initiated to quantify groundwater fluxes of nitrogen and microbial contaminants from cesspools in the Waimanalo "beach lot" neighborhood to
Waimanalo Bay. To estimate these fluxes, we analyzed groundwater quality and well head data from four monitoring wells within, and inland of, the beach lot region.
Head fluctuations provided information on local geohydrologic parameters and on the degree to which the monitored wells were hydraulically connected. Water sample
analyses provided data on the absolute concentrations of chemical species and microbial populations.
In general, we expected groundwater to flow predominantly toward the ocean, with groundwater in the two mauka wells representing water unaffected by cesspool loading,
and water in the two makai wells showing the accumulated effects of cesspool inputs of nitrogen and microbes. Two wells were installed and monitored in the mauka and
makai regions to provide replication of conditions in each of these areas. Surprisingly, the results obtained in this study demonstrate that groundwater in the study
area does not appear to flow directly from the mauka to makai wells, and that in fact the aquifers sampled by the mauka and makai wells may not be hydraulically connected
to any significant degree. As a result, we were unable to use the data obtained in this study to estimate nutrient and microbial fluxes to coastal waters in the manner
originally intended.
Despite our inability to directly quantify fluxes, the data provided by this study do allow us to reach some tentative conclusions regarding the probability of nutrient
and pathogen delivery to coastal waters. Overall, it appears that the potential for denitrification, which is the only process capable of permanently removing cesspool
nitrogen from groundwaters, is relatively small. As a result, the bulk of groundwater nitrogen probably does reach~coastal waters. Microbial transport appears to be
less likely, as groundwater sampled within the beach lot region was only occasionally found to contain measurable levels of indicator organisms, suggesting that the
sandy soils in the beach lot region may be relatively efficient at filtering bacteria from cesspool effluent. Better quantification of the actual magnitude and
pathway(s) of cesspool nitrogen delivery to coastal waters, and of the overall risk of pathogen delivery to coastal waters can be obtained by monitoring additional
wells in the beach lot region. Additional wells in the mauka region would also resolve flow details in that region and allow an integrated assessment of groundwater
nitrogen transport in this portion of the Waimanalo watershed. Given the apparent complexity of groundwater flow in the region, and the variety of sources that may
be affecting groundwater nitrogen levels, additional study is required to adequately characterize the magnitude and importance of cesspool nutrient and pathogen
contributions to groundwater.
Unedited Report WRRC-97-01 February 1997
ABSTRACT
In this study, the potential is evaluated for viral contamination of groundwater in the southern Oahu aquifer, Hawaii, due to irrigation of sugarcane with
effluent from secondary treatment plants. An EPA numerical model, CANVAS, has been modified and applied to simulate virus transport and its distribution in the
subsurface of several sugarcane fields near the Pearl harbor area. By incorporating the model with Monte Carlo simulations, the uncertainties and heterogeneity
of the subsurface could be accounted for to some degree. The simulations show that due to natural disinfection provided by the geological and hydrological conditions
in the testing fields, there is very low probability that viruses transported from irrigated fields by recharge water will reach drinking-water wells, although virus
concentration at the water table beneath the sugarcane fields is higher than a given criterion, 2 x 10' PFU/1. This is mainly due to the large backup distance between
the wells and the virus sources, which allows viruses to die off before they reach the wells. The study suggests that a reasonably long setback distance is necessary
for the areas where the thickness of soil is not large enough to allow all viruses to die off before they reach the water table or drinking water wells. In addition,
care must be taken when the temperature in the subsurface is not high enough to assist in the disinfection process. Unedited Report WRRC-96-10 October 1996
ABSTRACT
The objectives of this project are to evaluate operations, make recommendations,
and train personnel at the Schofield Barracks Wastewater Treatment Plant (SBWWTP)
for the purpose of improving the operating efficiency of the plant. There are
several tasks associated with this study, including (1) implementing a process
monitoring program, (2) determining treatment capacities, (3) developing process
control strategies, (4) providing technical guidance, (5) review/update operations
and maintenance manual, and (6) conducting mini-studies.
Like the first progress report, this second quarterly progress report contains
a brief summary of the more important findings obtained thus far and descriptions
of in-progress efforts. In the first report it was stated that all of the in-plant
flow meters were in serious need of calibration and this was an impediment to
progress. We are pleased to report that this is no longer the case. At approximately
the beginning of September, all of the in-plant flow meters were apparently
calibrated. This has allowed us to make increased progress on Task 2.
Since the first quarterly progress report we have continued to collect and
analyze a large quantity of samples from the treatment plant in order to characterize
all process streams (Task 1). In this report, these data are presented and summary
calculations of treatment efficiency have been prepared for primary clarification,
activated sludge, secondary clarification, and dissolved air flotation thickening
(DAFT). We have also been able to prepare preliminary solids balances for the
entire plant under current conditions and under more desirable conditions (smaller
sludge wasting rate and higher efficiency DAFF operation).
Based upon the results of process monitoring efforts, planning and/or implementation
of several mini-studies have been initiated as in-progress efforts (Task 6)
including: a DAFT performance study, an anoxic selector study, a bioaugmentation
study, and an activated sludge stress test. We should have results from these
studies for the next progress report.
Specific goals for the third quarter of this project include:
Unedited Report WRRC-96-09 July 1996
ABSTRACT
The overall objectives of this project are to evaluate operations, make recommendations,
and train personnel at the Schofield Barracks Wastewater Treatment Plant (SBWWFP)
for the purpose of improving the operating efficiency of the plant. The main
tasks associated with this study are as follows:
This first quarterly progress report contains a brief summary of the more important
findings obtained thus far as well as descriptions of in-progress efforts. To
date, considerable effort has been expended toward task (1) above through collection
and analysis of samples from the SBWWTP. Efforts have begun on tasks 2, 3,4,
and 5. The only current progress impediment is in regard to the need for accurate
data from all plant flow meters. Currently, many of the flow meters provide
questionable values and are in serious need of calibration. We cannot complete
the determination of projected treatment capacities or recommended process control
strategies without accurate flow data.
The extensive data collection program that we have initiated has enabled us
to get a reasonable picture of how the SBWWTP performs under existing conditions
and to begin determining process efficiencies/deficiencies (Task 2, above).
The data indicate some flow splitting problems (primary clarifiers and secondary
clarifiers), and a solids process stream limitation. The data also indicate
that the primary clarifiers function relatively well, that the activated sludge
process functions well and achieves complete nitrification despite a fairly
serious bulking problem, that there may be a problem with how effluent biochemical
oxygen demand (BOD5) samples are analyzed, that operation of the dissolved air
flotation thickener (DAFF) needs to be optimized, that the anaerobic digester
is not achieving acceptable solids stabilization, and that the centrifuge is
not achieving optimum sludge dewatering. All of these identified issues are
being addressed as in-progress effort.
Unedited Report WRRC-96-08 December 1996
ABSTRACT
Groundwater contamination caused by agricultural fertilization is a widely
recognized problem. In Hawaii, nitrogen fertilization from pineapple and sugarcane
fields has posed a threat to several basal aquifers and has been implicated
in coastal algae blooms. The concentration of nitrate-N in the Pearl Harbor
basin on the island of Oahu was below 2.3 mg/L in the 1950's and 1960's, and
has increased to as much as 7.6 mg/!... in 1992 to 1994. The objective of this
dissertation research is to develop a practical methodology for realistically
estimating nitrate leaching from fertilized agricultural lands.
Numerous mechanisms have impact on the distribution and migration of nitrate
in the soil. Nitrogen fertilizer undergoes many N transformations and interactions
with the soil and the plant after applications. In this study, an analysis of
soil samples was performed to understand the leaching process of nitrate in
the root zone of three different cropped fields in Hawaii. A detailed discussion
is given to address various factors which control the nitrate transport process.
To judge the sampling plan in relation to spatial variation, the field measurements
were evaluated statistically by an uncertainty index, which is represented as
the density of samples required for the estimate of sample mean of the nitrate
concentration to fall within a defined limit of accuracy.
In order to predict the effect of nitrogen fertilization on the groundwater
contamination with very limited input data, a simple, analytical, lumped parameter
model (LPM), was developed. The model can estimate the average nitrate leaching
from the root zone in response to agricultural practices, N transformations
and other related processes. The model was tested against the field data and
two detailed numerical models, LEACFLM-N and CERES-Maize. It provides an alternative
way to assess nitrate leaching from the root zone with acceptable accuracy.
A listing of the program is provided in Appendix 2.
Owing to the complex nature of nitrogen behavior in the unsaturated zone, some
degree of uncertainty is involved in the development of modeling approaches.
In this study, five major sources of uncertainty were identified. These are:
uncertainty due to spatial variation, uncertainty related to the accuracy of
the input data, uncertainty due to simplifications in the development of the
models, uncertainty due to modeling parameters, and uncertainty due to the complexity
of the unsaturated zone in Hawaii. The impact of these uncertainties on simulation
results is evaluated.
Unedited Report WRRC-96-07 December 1996
ABSTRACT
Groundwater contamination by agricultural fertilization is a widely recognized
problem in the USA and worldwide. Here in Hawaii, agricultural fields have posed
a threat to the invaluable basal aquifer. The concentration of nitrate-N in
the Pearl Harbor aquifer on Oahu was below 2.3 mg/L in the 1950's and 1960's,
but has increased in some wells in the Kunia area to a maximum of 7.6 mg/L in
1992 to 1994. The objective of this study is to assess nitrogen use in the agricultural
lands and nitrate contamination in the Pearl Harbor aquifer.
Nitrate distribution and migration in the subsurface are influenced by many
mechanisms. Nitrogen fertilizer undergoes many N transformations and interactions
with the soil and the plant after applications. In this study, a field data
collection was done and analysis of the samples was completed to understand
the leaching process of nitrate in the root zone of three different cropped
fields. A detailed discussion is presented to address various factors that control
the transport process. Field measurements were evaluated statistically to judge
the sampling plan in relation to spatial variations. The study uses an uncertainty
index in the analysis, which is the density of samples required for a sample
mean to fall within a defined limit of accuracy.
To simplify the process of estimating leaching rates to the aquifer, a simple
lumped parameter model (LPM) was developed. The model, which is analytical in
nature, uses a limited set of input data. Average leaching rates can be estimated
in response to agricultural practices, N transformations, and other processes.
The model is tested against two detailed numerical models with great success.
The model will be made available for interested parties for use in assessing
the potential threat to aquifers.
Various types of uncertainties affect our ability to predict nitrate fate accurately.
Five major sources of uncertainty were identified in this study: (1) uncertainty
due to spatial variation, (2) uncertainty related to the accuracy of the input
data, (3) uncertainty due to simplifications in the development of the models,
(4) uncertainty due to modeling parameters, and (5) uncertainty due to the complexity
of the unsaturated zone in Hawaii. The impact of these uncertainties on the
simulations of nitrate leaching is evaluated and a sensitivity analysis was
done to quantify the uncertainty due to the modeling parameters in a leaching
model. The result showed that hydraulic properties, plant uptake, and dispersivity
are very important in achieving reliable simulation or prediction. It is recommended
that hydraulic conductivity and water retention relationships be measured under
field conditions before the use of the model. A historical record of specific
plant growth and nutrient assimilation by the plant can provide reasonable data
for modeling the plant uptake process. Dispersivity can be obtained by calibration
of the model in a specific soil.
Although the sensitivity analysis suggests that uncertainty in nitrate adsorption
exert a considerable effect on nitrate transport results, anion adsorption is
not a principal factor that affects nitrate leaching in the root zone. The relatively
high content of organic matter in the root zone may favor a net negative surface
charge on soil colloids, which contributes to the leachability of negatively
charged nitrate. In contrast however, retardation of nitrate plays a dominant
role in nitrate leaching below the root zone in central Oahu. Only a small fraction
of the nitrate leaching reaches the groundwater. Although different explanations
have been proposed for the sorption process in the thick unsaturated zone in
central Oahu, a retardation factor should be considered for interpreting the
results of the outflow from the root zone.
Nitrate contamination in the Pearl Harbor aquifer was assessed. Quasi three-dimensional
models were used to simulate water flow and nitrate transport in the aquifer.
The models were calibrated by using available records and used for predictions
based on assumed scenarios for water and land use. Future predictions show the
likelihood of a nitrate contamination problem. Assumed conservative nitrate
concentrations at the water table and a very mild increase in water use resulted
in concentrations that exceed the MCL for nitrate of 10 ppm. Nitrate concentration
below the agricultural lands is likely to increase with planned land use changes
that may require additional fertilizer use. The possibility of changes in the
physical or chemical ability of the unsaturated deep formations to store nitrate
may also lead to increased leaching rates. A need exists for a better management
of fertilizer use, a process that should be possible without sacrificing agricultural
productivity. The approaches developed in this study can help in such an endeavor.
Unedited Report WRRC-96-06 December 1996
ABSTRACT
Petroleum hydrocarbon contaminants in soil may leach to the groundwater and
pose a threat to the quality of drinking water in Hawaii. This study was initiated
to evaluate the competence of tropical bacteria, indigenous to Hawaii, to degrade
petroleum hydrocarbons in soil when environmental factors are optimized to favor
the growth of microorganisms. In a first experiment, baseline microbial populations
were determined in five soils, then the soil was treated with either fertilizer
or fertilizer and 3,000 mg/kg of diesel No. 2 and incubated for 20 days. Heterotrophic
bacteria arid phenanthrene-degrading bacteria were enumerated on plates, total
bacteria were determined by microscopy (acridine-orange counts), and hexadecane-degraders
were enumerated by the most-probable-number technique in multi-well plates.
The double-layer-phenarithrene plates were modified to optimize enumeration
and isolation of bacteria. Hexadecane and phenanthrene-degraders were found
in all soils and were stimulated by the addition of diesel and fertilizer. Thus,
Hawaii soils harbor microorganisms that can be active in the bioremediation
of petroleum-contaminated soils.
Of the 200 bacteria that were isolated from either the phenanthrene plates
or the MPN-hexadecane wells, 70 could utilize as sole carbon source at least
one of the following hydrocarbons: hexadecane, diesel, mineral oil, phenanthrene,
arid pyrene. Most isolates were specialized in their use of hydrocarbons. Of
the 32 confirmed Gram-negative bacteria, 26 were identified by the Biolog~ system
as belonging to the genera Pseudomonas, Sphingomonas, Acinetobacter, and Flavobacterium;
the other 6 could not be identified. None of the 16 Gram-positive rod-shaped
hydrocarbon degraders was identified by the Biolog~ system.
The second experiment was a time-course experiment (124 days) in a chronically
contaminated soil (87 ppm of gasoline). This soil (#9) was spiked with 6,000
mg of diesel No. 2/kg, fertilized, and incubated in jars at 30°C and 40° C.
The higher temperature was used to simulate the increase in temperature which
may occur when bioremediation is conducted in a tent exposed to the sun under
tropical conditions. Three rapid techniques (less expensive than gas chromatography)
were evaluated to monitor the disappearance of hydrocarbons: gravimetry of a
hexane extract to measure total petroleum hydrocarbons (TPH), an immunoassay
to determine the concentrations of polycyclic aromatic hydrocarbons (PAN), and
the Microtox~ assay to determine soil toxicity. The concentration of TPH and
PAN decreased rapidly during the first month (25 and 10% left, respectively)
and then declined very slowly in soil containing active microorganisms. Soil
toxicity decreased with time. Similar results were obtained at 30°C and 4 0°C.
The concentrations changed little in soil where the microorganisms had been
killed with 0.5% HgCl2. CO2 evolution by the soil confirmed the growth of microorganisms
on diesel No. 2.
Determination of TPH by gravimetry and of PAN by immunoassay were more rapid,
informative, and cost-efficient methods than the Microtox assay. Bacterial counts
increased during the first 40 days, then remained stationary (total bacteria)
or decreased (hydrocarbon degraders).
In the third experiment, the possible enhancement of bioremediation of soil
contaminated with diesel No. 2 and No. 6 (Bunker C) by inoculation with a versatile
hydrocarbon-degrading bacterium (138) was examined. A clayey soil was contaminated
with 6,000 mg/kg of either diesel fuel, limed, fertilized, seeded or not with
bacterium 138, limed, fertilized, and incubated in jars at 30°C for 138 days.
Poisoned controls (0.6% HgCl2) were used to determine the extent of hydrocarbon
degradation due to microbial activity. A rapid biodegradation of TPH (75% in
14 days) occurred in soil contaminated with diesel No. 2, regardless of bacterial
seeding. Biodegradation of PAN was more gradual but reached 90% by day 98 in
both seeded and unseeded treatments. Inoculation (5 x i0~ bacteria/g of soil)
increased the counts of phenanthrene-degrading bacteria and of microorganisms
capable of utilizing hexadecane and diesel No. 2. The counts of total bacteria
and CO2 evolution were not increased by seeding. In soil contaminated with diesel
No. 6, the measurements of TPH and PAN were more variable due to the uneven
distribution of the product. The extent of the bioremediation of diesel No.
6 in this soil is unclear from these measurements. The counts of total bacteria
remained unchanged after the addition of diesel No. 6. However the counts of
the indigenous phenanthrene-degrading bacteria increased dramatically (4 log
units) during the first 54 days whereas the level of the seeded bacteria remained
stable. The counts of mineral oil degraders decreased steadily possibly due
to the toxicity of diesel No. 6. A small effect of seeding was visible (54 to
138 days) in the amount of CO2 evolved by the soil contaminated with diesel
No. 6. In conclusion, diesel No. 2 was readily degraded by soil microorganisms
while diesel No. 6 was more refractory. In this soil and with the Gram-positive
bacterium we used there was no detectable effect of inoculation on the extent
of bioremediation. Other soils and inoculants should be examined before definitive
conclusions can be drawn.
Unedited Report WRRC-96-05 May 1996
ABSTRACT
The construction of high-rise buildings and other engineering structures in
the downtown Honolulu area requires detailed site investigations prior to design
and construction. This includes soil borings, environmental assessments, and
groundwater measurements. As a result, much data on the subsurface geology of
downtown Honolulu exists, but it is spread among individual consulting firms
and various government agencies. The purpose of this study is to compile the
existing data and interpret the subsurface geology, engineering geology, hydrogeology,
and environmental problems within the study area.
This study commenced with collecting and interpreting 2,276 soil boring logs
from consulting firms in Honolulu, along with the Groundwater Index database
and environmental databases from the State of Hawaii. The subsurface materials
are classified into nine categories: fill, lagoonal (low-energy) deposits, alluvial
deposits, coralline debris, coral ledges, cinders, tuft, basalt, and residual
soil or weathered volcanics. The study area is divided into 157 quadrangles
(1000' X 1000'). The subsurface conditions within each quad are described in
detail, and nine cross-sections are presented for further clarification of the
subsurface geology. Foundation bearing layers and buried alluvial channels are
mapped. Environmental problems and groundwater data are summarized in the form
of tables and maps.
The coral ledges, tuft, and basalt are the most suitable foundation bearing
layers within the caprock. The coral ledges, coralline debris, coarse-grained
lagoonal sediments, and cinder sands are characterized by higher hydraulic conductivities
than the other materials that comprise the caprock. However, the caprock as
a whole is characterized by much lower hydraulic conductivities than the underlying
Koolau basalt that is the main aquifer for the island. The caprock groundwater
is brackish, non-potable, and highly vulnerable to contamination. Petroleum
hydrocarbons and heavy metals from leaking underground storage tanks are the
primary soil and groundwater contaminants. Caprock groundwater is generally
found within ±5 feet of sea level. Dewatering is often necessary at sites involving
the construction of basements.
Unedited Report WRRC-96-04 September 1996
ABSTRACT
The discharge of treated domestic sewage into the ocean gives rise to a concern
that aquatic species which live in the area around the outfall are at an increased
risk for pollution related diseases. One approach to assess if such an impact
has occurred is to periodically monitor fish that have been captured from the
immediate vicinity of the ocean outfall for liver neoplasms and pre-neoplastic
changes.
The report is a summary of gross necropsy and liver histopathology findings
for 100 fish. A glossary of technical terminology is provided on pages six and
seven of the report.
PROCEDURES
For evaluation of liver histopathology, five species of fish were collected.
These were the akule, Selar crumenophthalmus, 35 specimens; ta'ape,
Lutjanus kasmira, 40 specimens and three species of menpachi: Myripristis
berndti, 20 specimens; M. murdjan, 3 specimens; and M. chryseres,
2 specimens. The fish were collected by staff of the Division of Wastewater
Management, City and County of Honolulu by hook and line methods. Fifty nine
of the fish were captured from the control station in Maunalua Bay. The depth
at which the fish were collected ranged 60 to 240 feet at the Maunalua Bay Station.
The other 41 fish were gathered from the area of the Sand Island Municipal Sewage
Outfall. The depth fish were collected ranged 90 to 260 feet at the San
Column Study of the Transport of Selected Contaminants in a Hawaii Soil Treated with Recycled Water. Project Report to Brown and Calsdwell, Inc..
Snehota, Michal, Joseph Lichwa, Martina Sobotkova, and Chittaranjan Ray.
Benthic Infaunal Communities Adjacent to the Sewage Outfalls at Agana and Northern District, Guam, Mariana Islands, 2005-2007.
Bailey-Brock, Julie H., and Emily R. Krause.
Evaluating the Effectiveness and Feasibility of Commercial Ozone Technologies Used for Sanitation of Work Area and Laundry Services.
Fujioka, Roger S., Dayna M. Sato, and Bunnie S. Yoneyama.
Fate and Transport of Selected Endocrine Disrupting Chemicals in Recycled Water Through a Tropical Soil. M.S. thesis
(Civil Engineering and Environmental Engineering),
Mohanty, Sanjay K.
Development and Implementation of a Water Monitoring Plan to Prepare for Criminal and Terroristic Contamination of a Drinking Water System.
Fujioka, Roger S., Audrey Asahina, Dayna Sato, and Bunnie Yoneyama.
Performance Evaluation of a CBT 0.8KF-210 Wastewater Treatment Unit.
Babcock, Roger W., Jr., Atiim Senthill, Tieshi Huang, Yingyot Chanthawornsawat, Sumon Kanpirom, and Jing Hu.
Assessing the Source of Fecal Contamination in Streams on Kauai Based on Concentration and Genotypes of FRNA Bacteriophages. M.S. thesis (Microbiology),
Vithanage, Gayatri.
Are Fecal Sterols a Possible Alternative Indicator of Human Waste Contamination in Hawaiian Recreational Waters? M.S. thesis (Microbiology),
Brostrom, Kathleen England.
User Manual for CLERS: Comprehensive Leaching Risk Assessment System.
Stenemo, Fredrik, and Chittaranjan Ray.
Improving Model Estimates of Pesticide Leaching for Hawaii Soils.
Stenemo, Fredrik, and Chittaranjan Ray.
Assessing the Microbial Quality of Potable Water Sources on the Island of Hawaii.
Fujioka, Roger S., Dayna M. Sato, Gayatri Vithanage, and Bunnie S. Yoneyama.
Column Study of the Transport of Selected Contaminants in a Hawaii Soil Treated With Recycled Water.
Snehota, Michal, Jingyu (Joey) Chen, Sanjay Mohanty, Joseph Lichwa, and Chittaranjan Ray.
Schofield Barracks Wastewater Treatment Plant Optimize Aeration, Secondary
Clarifier, and Disinfection Processes.
Victor Moreland
Analysis of Synagro Biosolid Pellets and Pellets Applied to Hawaiian Soil
for Detection and Growth of Salmonella
Roger S. Fujioka, Gayatri Vithanage, Bunnie Yoneyama
Assessing the Treatment of Cooling Tower Water Using the Electrocel Technology
System (ETS): Phase I. Project completion report prepared for Kilpatrick Enterprises,
Inc., Honolulu, Hawaii.
Roger S. Fujioka, and Audrey Asahina
Economic Impacts of Providing Secondary Treatment at the Sand Island Wastewater
Treatment Plant, Oahu, Hawaii
James E.T. Moncur
Assessment and Protection Plan for the Nawiliwili Watershed: Phase 2-Assessment
of Contamination Levels
Aly I. El-Kadi, Roger W. Babcock, Roger S. Fujioka, Clark C.K. Liu, Jacquelin
N. Miller, James E.T. Moncur, and Philip S. Moravcik
Assessment and Protection Plan for the Nawiliwili Watershed: Phase 1-Validation
and Documentation of Existing Enviromnental Data
Monika Furness, Aly I. El-Kadi, Roger S. Fujioka, Philip S. Moravcik
Effects of Reclaimed Water on Two Golf Courses Located Over a Potable Aquifer
in Central Oahu
Zhijun Zhou, Roger W. Babcock
Decontamination of the Former Grayline Baseyard: Phase I Project Completion
Report
Renee M. Harada, Aly I. El-Kadi, Francoise M. Robert
Assessing the Persistence and Multiplication of Fecal Indicator Bacteria
in Hawaii Soil Environment - PhD dissertation
Muruleedhara N. Byappanahalli
Wastewater Characterization at Various Treatment Levels from Oahu Wastewater
Treatment Facilities for UV Disinfection Suitability-Phase II: Collimated Beam
Studies
Roger S. Fujioka, Audrey Asahina, Victor Moreland, and Tuamasaga Unutoa
Wastewater Characterization at Various Treatment Levels from Oahu Wastewater
Treatment Facilities for UV Disinfection Suitability - Phase I: Liquid Stream
Studies
Roger S. Fujioka, Audrey Asahina, Victor Moreland, and Tuamasaga Unutoa
Sand Island Wastewater Treatment Plant Disinfection Study
Roger S. Fujioka, Audrey Asahina, Victor Moreland, and Tuamasaga Unutoa
Evaluation of the Disinfection Efficiency of Safe Water Systems Solar Pasteurization
Unit Following Design Modifications
Roger S. Fujioka and Geeta Rijal
Studies on Chemical Regeneration of Granular Activated Carbon
Roger W. Babcock Jr., and Sumita Thakur
Bench Study of Chlordane and Dieldrin Adsorption: Final
Roger W. Babcock Jr., Elisa Amantiad, Christine Ishikawa, and Mitch Uehara
Correlation of Activity Measurements and Most Probable Number Counts During
Bioaugmentation of Activated Sludge
Anke Wellbrock and Roger W. Babcock, Jr.
The Potential Environmental and Public Health Effects of Chemical Regeneration
of Spent Granular Activated Carbon
Tracy K. Fukuda, Roger W. Babcock, Jr., and Premlata Menon
Performance Evaluation of an OESIS-750 Residential Wastewater Treatment Unit
Roger W. Babcock Jr., Daniel A. McNair, and Lance J. Edling
Water Quality Evolution and Analytical Method Equivalency Testing for Hawaiian
Fishponds on Moloka'i
Oshiro, Hisato 'Keith' and Roger W. Babcock, Jr.
Vulnerability to Pathogens: Phase 2. Monitoring Groundwater for Human Enteric
Viruses by Culture and Genetic Probe (PCR) Methods
Roger S. Fujioka, Audrey Asahina, Geeta Rijal, and Fred Bonilla
An Innovative Approach to Assess and Monitor the Quality of Coastal Waters
Roger S. Fujioka, Geeta K. Rijal, and J. Alfredo Bonilla
Literature Review of GAC Regeneration Methods and Local Disposal Alternatives
Damon Hamura, Arlene Sagayaga, and Roger Babcock, Jr.
Sorption, Desorption, and Biodegradation of Natural Organic Matter and Pesticides
on Spent Granular Activated Carbon
Roger Babcock Jr., Veronica Ewald, and Mitch Uehara
Assessing the Ambient Microbial Quality of Marine Water Surrounding the Waikiki
Natatorium
Roger S. Fujioka Geeta Rijal, and Alfred Bonilla
Development of a Feasible Method to Detect Pathogenic Leptospira Bacteria
in Environmental Waters
Roger S. Fujioka and Audrey Asahina
Simulation of Pesticide Transport in Macroporous Soils
Using a Dual-Porosity Approach
Chittaranjan Ray
Simultaneous Removal of Carbon and Nitrogen by Using a Single Bioreactor for
Land Limited Application<BR>
Keping Cao
Microbial Assessment of the Lana'i Auxiliary Reclamation Facility to Produce
Wastewater Effluent for Unrestricted, Non-Potable Use
Roger S. Fujioka Alfred J. Bonilla, and Geeta K. Rijal
Effect of Bioaugmentation and Diesel Fuel Type on Soil Bioremediation
Barrie Wu Chua-Chiaco
Do Fecal Bacteria Multiply in the Soil Environments of Hawai'i?
Roger S. Fujioka and Muruleedhara N. Byappanahalli
Roger S. Fujioka, Audrey Asahina, Victor Moreland, and Tuamasaga Unutoa
Collaborative National Study Using Molecular Techniques to Detect Hepatitis
A Virus and Virulence Factor Genes in E. coli: Hawai'i Matching Study
Roger S. Fujioka, Bruce M. Roll, and Alfred J. Bonilla
Vulnerability to Pathogens: Water Quality Monitoring and Assessment Study
Roger S. Fujioka and Bunnie S. Yoneyama
Schofield Barracks Wastewater Treatment Plant Process Control Program: Quarterly
Progress Report No. 3
Collins Lam, G. Dennis Lopez, Cey Murakami, Qing Lin, Ann Bin Lin, and Roger
Babcock, Jr.
Integrating an Intermittent Aerator for a Swine Wastewater Treatment System
Wang, Zhiyu
Assessment of Nitrogen and Microbial Contributions of Waimanalo "Beach Lot"
Cesspool Systems to Groundwater
Daniel J. Hoover and Tua M. Unatoa
Modeling of Virus Transport in the Subsurface, Southern O'ahu, Hawai'i
Shlomo Orr and Jing Li
Schofield Barracks Wastewater Treatment Plant Process Control Program: Quarterly
Progress Report No. 2
Collins Lam, G. Dennis Lopez, Cey Murakami, Qing Lin, Ann Bin Lin, and Roger
Babcock, Jr.
Schofield Barracks Wastewater Treatment Plant Process Control Program: Quarterly
Progress Report No. 1
Collins Lam, G. Dennis Lopez, Cey Murakami, Qing Lin, Ann Bin Lin, and Roger
Babcock, Jr.
Assessment of Nitrate Leaching in the Unsaturated Zone on O'ahu
Ge Ling
Assessment of Nutrient Use and Nitrate Contamination in Central O'ahu, Hawai'i
Ge Ling , Aly I. El-Kadi, and Keith Yabusaki
Bioremediation Potential of Petroleum Hydrocarbon-Contaminated Soils Under
Tropical Conditions
Francoise M. Robert
Subsurface Geology and Hydrogeology of Downtown Honolulu With Engineering
and Environmental Implications
Suew-Ann Finstick
A Report of the Necropsy and Liver Histopathology Findings for Fish Sampled
From the Control Station in Maunalua Bay and the Sand Island Outfall, June-July
1995
James A. Brock