WRRC Special Reports

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WRRCSR No. 97-02 Technologies and Strategies Used in Okinawa: Third Symposium on Hawiai/Okinawa Water Resources
(Water Resources Research Center, University of Hawaii at Manoa, 1997-08)
WRRCSR No. 96-01 Assessment of Groundwater Models: 1994
(Water Resources Research Center, University of Hawaii at Manoa, 1995-07)
Assessment of groundwater models was the focus of the Pacific Northwest/Oceania conference held on March 21-23, 1994, at the Turtle Bay Hilton, Oahu, Hawaii. This conference differed from other modeling meetings by focusing on critical assessment-to what extent models have been adequate to address water, land, and environmental problems and have been able to advance scientific understanding of groundwater systems. These needs have been made acute by the very popular use and sometimes misuse of computational (numerical) models in recent years. Consequently, the crucial issue is, what is needed in the next generation of models in light of the critiques?
WRRCSR No. 9:23:83 Rainfall Frequency Study for Oahu: Option 1--Preparation of Rainfall Frequency Maps
(Water Resources Research Center, University of Hawaii at Manoa, 1983-09) Giambelluca, Thomas W.; Lau, L. Stephen; Fok, Yu-Si; Schroeder, Thomas A.
Annual maximum rainfall series at 157 gages were used to evaluate extreme value rainfall. Daily fixed-interval data were adjusted by a factor of 1.143 to represent true maxima. Records of short-term stations were extrapolated by regional analysis. Gumbel extreme value, log-Pearson Type III, and log-normal distributions were tested for applicability and found to have approximately equal goodness-of-fit. The Gumbel distribution was used, fitted by the method of moments. A topographically based interstation interpolation model was developed as an aid in mapping maximum rainfall for durations of 1-, 6-, and 24-hr and return periods of 2-, 10-, 50-, and 100 years.
WRRCSR No. 9:19:86 Rotating Biological Contactor Pilot Study: Fort Kamehameha Wastewater Treatment Plant, Pearl Harbor, Hawaii
(Water Resources Research Center, University of Hawaii at Manoa, 1986-09) Dugan, Gordon L.; Takiguchi, Dean K.
A self-contained pilot unit (including primary and secondary sedimentation) complete with electric motor driven plastic discs (surface area approximately 500 ft2), located at the U.S. Navy's 7.5 mgd Fort Kamehameha Wastewater Treatment Plant (WWTP) at Pearl Harbor, O‘ahu, Hawaii, was operated from July 1985 to July 1986 at four different operating modes: hydraulic loadings of 1.5, 3.0, and 5.0 gpd/ft2 (flat disc area) with discs exposed; and 5.0 gpd/ft2 with discs covered. The influent for the RBC unit was primary clarifier effluent, which was very brackish for wastewater (4000-5000 mg/l chloride). In addition, wastewater from industrial-type operations that use and discharge controlled/treated concentrations of heavy metals were received at the WWTP. The median effluent BCDs concentrations for the first two hydraulic loading rates (1.5 and 3.0 gpd/ft2) were respectively 2.0 and 8.0 mg/l, with corresponding respective median suspended solids values of 8.0 and 7.5 mg/l. These values were comparable with the present WWTP operation utilizing the activated sludge process. Hydraulic loadings at 5.0 gpd/ft2 provided median effluent BOD5 concentrations in the 30 to 35 mg/l range. Heavy metal concentrations in the wastewater flows of the WWTP and RBC unit were considerably below the level of concern, while some accumulation of heavy metals was noted for the higher concentrations of suspended and settled solids--the mixed liquor suspended solids and the raw and digested sludge. Replacing the existing activated sludge component with an RBC component being hydraulically loaded at 3.0 gpd/ft2 would require an estimated capital cost of approximately $2,500,000, which would require nearly 20 years to repay in electrical cost savings, based on a 10¢/kWh electrical cost, that increases in cost at an annual rate of 5%, and an interest rate of 8% compounded annually.
WRRCSR No. 7:85 Subsurface Water and Soil Quality Data Base for State of Hawai'i, Part 1
(Water Resources Research Center, University of Hawaii at Manoa, 1985-07) Oki, Delwyn S.; Giambelluca, Thomas W.
In recent years, various chemical contaminants have been detected in Hawai'i’s groundwater sources. Several agencies in Hawai'i have been monitoring the groundwater quality for the contaminants, dibromochloropropane (DBCP), ethylene dibromide (EDB), and trichloropropane (TCP). In addition, several agencies have investigated the movement of these compounds in the soil at various sites on O'ahu and Maui. The Data Base which accompanies this report represents an effort to compile all available results from these agencies and to organize than into a uniform, computer-readable system in order to facilitate research on the extent, movement, and persistence of contaminants in the soil and groundwater of Hawai'i. Results from analyses performed on water samples taken from wells, springs, and from points within various water distribution systems throughout the state, as well as results from analyses performed on soil samples taken at sites on O'ahu and Maui are included herein. The primary emphasis of the Data Base is on the compounds DBCP, EDB, and TCP, but other pertinent compounds are also included. A data summary table of the maximum concentrations of these three compounds present in well and spring water samples is included as a part of this report.
WRRCSR No. 07:21:87 Aquifer Recharge by Irrigation with Primary Effluent: Field Experiments with California Grass and Sugarcane
(Water Resources Research Center, University of Hawaii at Manoa, 1987-07) Lau, L. Stephen
The 'Ewa caprock aquifer has been a long-standing water source for southern Oahu, but the freshwater viability of the aquifer is being threatened with a gradual increase in the salinity level of pumped aquifer water in recent years. Concern over enhancing the freshwater quantity and quality of the 'Ewa caprock aquifer prompted a consortium of six agencies to sponsor a demonstration “Groundwater Recharge with Treated Wastewater Effluent” project.
WRRCSR No. 7.5:85 Drilling Program and Pesticide Analysis of Core Samples from Pineapple Fields in Central O'ahu
(Water Resources Research Center, University of Hawaii at Manoa, 1985-11) Peterson, Frank L.; Green, Kim R.; Green, Richard E.; Ogata, Janice N.
As part of the ongoing research of the WRRC Subsurface Water Quality Project, a drilling program was begun in October 1985 to collect soil and saprolite core samples from sites located in central O‘ahu pineapple fields. Samples were analyzed for concentrations of fumigant pesticides used in pineapple cultivation. These included EDB (ethylene dibromide), DBCP (dibromochloropropane), and TCP (trichloropropane) which originated in the pesticide Shell DD applied over 30 years ago. Results from the analyses are expected to provide current information on the subsurface movement of these toxic organic compounds. Thus far, pesticide analyses have been completed for five test boreholes in Dole fields (D-4201A, D-4201B, D-4213B, D-4111W, D-4101), in which residual pesticides have been detected in the first three. None were detected in boreholes D-4111W and D-4101. Additional core samples were collected and preserved intact from the same boreholes for physical, hydraulic, and mineralogical measurements to be performed at a later time. These intact or "undisturbed" core samples can be used to characterize and relate the structural and mineralogical properties of the samples and to determine the importance of such properties on the deep percolation of water and the associated transport of residual pesticides.
WRRCSR No. 7.4:85 Deep Percolation of Water from Pineapple Fields
(Water Resources Research Center, University of Hawaii at Manoa, 1985-11) Giambelluca, Thomas W.; Oki, Delwyn S.
Efforts are being made to identify the sources, concentrations, spatial extent, movements, and rates of degradation of recently detected groundwater contaminants in Hawai'i. A spatially detailed evaluation of the time series of water percolation is required so that leaching from the top soil, downward transport through the profile, and eventual movement of the pesticides within the basal groundwater may be estimated. Using the water balance method, the 1946 through 1983 sequence of downward percolating water will be estimated for each present and former pineapple grating area of central O'ahu. Thus far, work on this project has focused on land-use identification, parameter evaluation, and data gathering. Results obtained using the same model in a previous study indicate that ET-suppression by pineapple causes percolation to be significantly higher than that experienced under a natural vegetative cover. This may account for the unexpected movement of these chemicals through the great thickness separating the pineapple fields from the basal water table.
WRRCSR No. 7.3:85 Spatial and Temporal Distribution of Contaminated Basal Water in Southern and Central O'ahu Aquifers
(Water Resources Research Center, University of Hawaii at Manoa, 1985-11) Oki, Delwyn S.; Giambelluca, Thomas W.
In recent years, several pesticide-related contaminants have been detected in the basal waters of southern and central O'ahu aquifers. Dibromochloropropane (DBCP) and ethylene dibromide (EDB), two soil fumigants which were previously used by pineapple growers in southern and central O'ahu, have been discovered in several wells in the area. A third contaminant, trichloropropane (TCP), which is an impurity of the soil fumigant DD, has also been detected in a number of wells. DBCP, EDB, and TCP are of particular concern to state public health officials due to the known and possible unknown health effects associated with these compounds. This is especially true for the Pearl Harbor Aquifer, which is the major potable water source for Honolulu. Thus, it is imperative to have an understanding of the extent and movement of the contamination. The locations of the contaminated well sites appear to be correlated with the areas of past and present pineapple cultivation when the ambient groundwater flow pattern is taken into consideration. In addition, several significant pipeline leaks of petroleum products (aviation fuels) in the vicinity may have contributed to the EDB contamination. An analysis of the temporal variation of contamination in selected wells indicates no significant fluctuation in contaminant levels over a one-year study period from 1 September 1983 to 1 September 1984.
WRRCSR No. 7.2:85 Exploratory Study Using Water Disinfectants to Remove EDB from Clean Water
(Water Resources Research Center, University of Hawaii at Manoa, 1985-11) Fujioka, Roger S.; Narikawa, Owen T.; Yoneyama, Bunnie S.
A reliable and practical method is required to reduce the concentrations of hazardous chemicals (EDB, DBCP, TCP) which have been detected in some of the groundwaters used for drinking on O'ahu. This study evaluates the feasibility of using high concentrations of water disinfectants to oxidize (reduce) the concentrations of EDB in water. Water seeded with 100 ppt to 20 ppb of EDB were treated with various doses of disinfectants (chlorine, chlorine dioxide, hydrogen peroxide, ultraviolet light, ultraviolet light plus hydrogen peroxide). The concentrations of ED3 in water samples before and after treatment with these disinfectants were determined using liquid-liquid partitioning to extract the EDB and gas chromatography to measure the concentrations of EDB. The results of this study indicated that 5 to 5,000 mg/l of chlorine and 2 to 50 mg/l of chlorine dioxide are incapable of reducing the concentrations of EDB in water. The ability of 3 and 10% hydrogen peroxide to reduce the concentrations of EDB in water was erratic. In some experiments, no reduction of EDB was observed while in other experiments up to 45% of the EDB was apparently oxidized. Ultraviolet (UV) light alone removed only 10% of the EDB. The most promising system was the use of UV light plus 3 or 10% hydrogen peroxide. When this system was used, 33 to 75% of the EDB in the water was reduced. Thus, further studies assessing the feasibility of using UV light and hydrogen peroxide to remove and other toxic chemicals in water is recommended. However, hydrogen peroxide is available in a liquid state at 30% and therefore it is impractical to treat large volumes of water with high concentrations of hydrogen peroxide. In this regard, ozone is chemically similar to hydrogen peroxide but is more reactive. Ozone can also be generated as a concentrated gas and apparatus for the treatment of large volumes of water with UV light and ozone is commercially available. It is therefore recommended that further studies be done to determine the feasibility of using UV light and ozone to remove the concentrations of EDB in water.
WRRCSR No. 7.1:85 Desorption and Leachability of Residual DBCP and EDB from Soils and Saprolite
(Water Resources Research Center, University of Hawaii at Manoa, 1985-11) Green, Richard E.; Peterson, Frank L.; Buxton, Donna S.
Pesticides applied to pineapple fields in central O'ahu to control nematode populations have been detected in groundwater drawn from the underlying aquifer. These nematicides have persisted in surface soils and deep saprolite despite their discontinued use. The leachability of these pesticide residues from soil and their subsequent movement will determine whether or not they constitute a continued threat to groundwater quality. In this study, leachability is assessed by sorption-desorption measurements and is characterized by distribution coefficients and the kinetics of release of sorbed residues. Two methods for characterizing sorption-desorption processes have been developed that exploit the tendency of these fumigant pesticides to vaporize. Both methods analyze the vapor phase of a soil-pesticide system. The indirect sorption method results in a determination of distribution coefficients and the purge system results in a characterization of the kinetics of desorption. Experiments using the indirect sorption method to determine distribution coefficients for a surface soil obtained from central O'ahu have been initiated. Preliminary work using the purge system is also underway. The new sorption-desorption methods will be used to determine the leachability of DBCP and EDB residues in soil and saprolite obtained from central O'ahu.
WRRCSR No. 7.0:85 Subsurface Water Quality Organic Chemical Contamination of O'ahu groundwater
(Water Resources Research Center, University of Hawaii at Manoa, 1985-12) Lau, L. Stephen
This progress report is a study of the unprecedented problem of low-level organic chemical contaminants discovered principally in 1983 in potable groundwater sources on O'ahu. A number of inmediate and serious concerns are (1.) extent of the contaminated basal water, (2) treatments capable of removing such low level contaminant concentrations, and (3) health effects to drinking water consumers. Short-term actions were undertaken by the Hawaii State Department of Health (DOH) regarding the potability question of the contaminated water and the associated health risk. (The DOH subsequently proposed 20 ppt as the maxinun limit of EDB and DBCP in drinking water and none for TCP, despite oontroversies and lack of definitive scientific basis.) As a result of closing water wells exceeding these limits, immediate action was needed and taken by the major water purveyors (City and County of Honolulu Board of Water Supply [BWS] and U.S. Navy) to replace the closed water sources and/or to treat the contaminated water to below the maximum level. The BWS and U.S. Navy decided on treatment plants and the State drilled two new wells. Expediency was the priority for these actions.
WRRCSR No. 5.25:83 Haina Well Water Analysis for Presence of Human Enteric Viruses and Other Water Quality Paramenters, Island of Hawai'i
(Water Resources Research Center, University of Hawaii at Manoa, 1983-05) Fujioka, Roger S.; Lau, L. Stephen
The primary purpose for the analysis of the Haina Well water by the Water Resources Research Center of the University of Hawaii at Manoa was to determine the presence or absence of human enteric viruses in the well water. Since coliform bacteria is currently the only indicator bacteria required by law to assess the hygienic quality of water, the total coliform and fecal coliform contents of the well water were tested. In addition, the water was also tested for fecal streptococcus, the most used alternative indicator of water quality, and for Clostridium perfringens, the most stable of the proposed indicator bacteria. Finally, as a check on the overall quality of the well water, selected chemical analyses of the water were also done.
WRRCSR No. 03.02.90 Assessment of the Potential for Groundwater Contamination Due to Proposed Urban Development in the Vicinity of the U.S. Navy Waiawa Shaft, Pearl Harbor, Hawaii
(Water Resources Research Center, University of Hawaii at Manoa, 1990-03) Oki, Delwyn S.; Miyahira, Robert N.; Green, Richard E.; Giambelluca, Thomas W.; Lau, L. Stephen; Mink, John F.; Schneider, Randi C.; Little, David N.
The concern over groundwater contamination in Hawaii has become most pronounced since the early 1980s with the discovery of various pesticide-related contaminants in the basal groundwaters of several of the state's aquifers. Two soil fumigants previously used by pineapple growers, 1, 2-dibromo-3-chloropropane (DBCP) and 1, 2-dibromoethane or ethylene dibromide (EDB), have been detected in several wells on Oahu and Maui. The compound 1,2,3-trichloropropane (TCP), which is an impurity of another soil fumigant DD, has also been detected in numerous wells on Oahu and Maui. The herbicide atrazine, commonly used by the sugarcane industry, has been found in wells on the islands of Hawaii, Maui, Oahu, and Kauai. In addition, the solvents trichloroethylene (TCE) and tetrachloroethylene (PCE) have been detected in Oahu groundwater samples. Prior to the recent discoveries of pesticides in the state's groundwaters, it was felt that the great depth (hundreds of meters) between the ground surface and the basal waters of the state's aquifers was sufficient to prevent leaching of pesticide residues to the water table. Furthermore, it was believed that any residues which did reach the basal aquifers would become so greatly diluted as to be undetectable. It is now clear, however, that the overlying soil, saprolite, and basalt layers do not completely insulate Hawaii's groundwaters from contamination. Chemicals applied by man at the ground surface can potentially reach the groundwater table.
WRRCSR No. 3.12:84 Rotating Biological Contactor for Brackish Wastewater Effluent Treatment
(Water Resources Research Center, University of Hawaii at Manoa, 1984-03) Dugan, Gordon L.
The rotating biological contactor CRBC) is an attached (fixed) growth, biological treatment unit which consists of closely spaced, rotating shaft-mounted discs that generally have approximately 40% of their surface submerged in wastewater. The RBC unit, which generally serves as a secondary treatment process, has only been used in the United States since 1969 and, as yet, has not been widely used in this country. On Oahu, Hawaii, RBCs have apparently not been used except for experimental purposes. Of the RBC studies that have been reported nationally and internationally, the efficiency of the RBC process has not been reported for tropical and subtropical climatic conditions for brackish wastewater. A bench scale RBC unit, utilizing settled, brackish wastewater effluent from the Sand Island Wastewater Treatment Plant on Oahu, showed that 5-day biochemical oxygen demand and suspended solids removals of approximately 90% and slightly less than 80% were achievable at typical (full-scale) hydraulic disc loading rates. Thus, salinity (at least chlorides up to 2000 mg/ ℓ) apparently does not seriously interfere with the RBC’s treatment efficiency.
WRRCSR No. 1.29:82 The Significance of the Bactericidal Effect of Sunlight on Indicator and Pathogenic Bacteria in Marine Waters on Measurements and Interpretations of Water Quality
(Water Resources Research Center, University of Hawaii at Manoa, 1982-01) Fujioka, Roger S.
Natural streams collect runoff and discharges from many sources which alter the quality of stream water. To determine the hygienic quality of streams, water samples from streams are collected and assayed for two human enteric bacteria, fecal coliform (FC) and fecal streptococcus (FS). These bacteria are non-pathogenic to man and are normal inhabitants of the intestinal tract of man and warm blooded animals. The concentrations of these bacteria in natural waters are used as indicators of fecal pollution and as a probability factor that pathogenic microorganisms may be present in that polluted water.
WRRCSR No. 1.10:83 Decontamination of Chromium-Contaminated Soil and Water: Pearl Harbor Naval Shipyard, Peart Harbor, Hawai'i, Phase 2
(Water Resources Research Center, University of Hawaii at Manoa, 1983-01) Dugan, Gordon L.; Gee, Henry K.; Lau, L. Stephen
Phase 2 of this project represents the analytical monitoring of an estimated 64,800 ft3 (1 835 m3) of chromium-contaminated soil, classified as a hazardous waste (>5 mg/ℓ chromium extract concentration as measured by the standard EP toxicity test), that was treated at the Pearl Harbor Naval Shipyard during a two-month period in late 1982. Although the treatment process details (wash-water-detention times, number of wash-water-flow-through times, and type and amount of chemicals) were the contractor's proprietary information, the analytical monitoring treatment process essentially followed the general treatment methods developed in Phase 1 (laboratory and pilot plant studies). The treatment performed by Advanced Environmental Consultants, Inc., of Pittsburgh, Pennsylvania consisted of utilizing 2 yd3 (1.53 m3) modified dumpsters as the soil receptacles, using upflow/downflow washing to leach the chromium from the soil, adding a reducing agent to chemically reduce chromium Cr+6 to Cr+3, raising the pH to approximately 8.5 to precipitate the chromium from solution and to dewater the chromium laden sludge. Each processed soil batch (nearly all 2 yd3 dumpster units) were monitored for chromium extract. Only 35 of approximately[sic] 1200 dumpster loads were above the 5-mg/ℓ limit, and these were reprocessed.
WRRCSR No.09:24:92 Granular Activated Carbon Treatment of Mililani Well Water: Phase II Study to Extend Effective Life of GAC, Six-Month Progress Report
(Water Resources Research Center, University of Hawaii at Manoa, 1992-10) Dugan, Gordon L.; Fujioka, Roger S.; Lau, L. Stephen; Takei, Gerald H.; Gee, Henry K.; McParland, Terra L.
The aerated Mililani well water, which removed about 40% of TCP, and spiked deionized water, intended to reduce the level of natural background organics, both appeared to increase the volume of water passing through the minicolumns before breakthrough by nearly 40%. Likewise the carbon usage rates for the spiked deionized water and aerated Mililani well water decreased in comparison to untreated Mililani well water, except for the March 1992 minicolumn experiment, which was nearly the same. More minicolumn tests will need to be performed to ascertain if the March 1992 minicolumn results were reasonable or, possibly an anomaly. The minimum minicolumn carbon usage values of approximately 0.022 lb/1000 gal did not simulate field operation values which ranged from 0.135 to 0.150 lb/1000 gal; however a close correlation would not be expected. In addition, the aerated Mililani well water samples did not increase the weight of TCP and DBCP that was able to be adsorbed by the pulverized GAC. Thus, it seems apparent that background material (presumably organic or primarily organic material) may be utilizing adsorption sites. No apparent relationship existed for TC or NPOC removal before and after breakthrough. Further minicolumn experiments will be continued to substantiate the minicolumn experimental data collected to date.
WRRCSR No.09:00.88 Wastewater Reuse By Irrigation in Hawai'i: May 1989 Update
(Water Resources Research Center, University of Hawaii at Manoa, 1989-05) Murabayashi, Edwin T.
A statewide survey was conducted to detennine the nature and extent of wastewater reuse by irrigation in 1989. An average of 13.985 mgd (million gallons/day) of wastewater is applied to 2115+ acres. Acreages are difficult to ascertain because with sugarcane much of the wastewater is highly diluted with other waters and distributed broadly to indeterminable acreages. The 1989 data were compared with an earlier survey conducted in 1977. Current reuse is approximately double the 7.18 mgd recorded in 1977. The two primary reuses statewide are for sugarcane and golf course irrigation, utilizing 7.382 and 6.288 mgd respectively. Since 3.5 mgd of the effluent applied to sugarcane is utilized irregularly, it is difficult to suggest any trends. Reuse on golf courses, on the other hand, has tripled from the 2.06 mgd in the earlier survey. This increase is attributable to gains on all islands but particularly on Maui. In the state, there are 24 treatment plant/reuse facilities of which twenty use domestic wastewater and four utilize farm animal wastes. On an island basis, Maui and O'ahu have the highest wastewater reuse, with 6.185 mgd and 5.072 mgd respectively, followed by Kaua'i (2.09 mgd), Hawai'i (0.528 mgd), and Moloka'i (0.11 mgd).
WRRCSR No.8:22:90 Municipal Incinerator Ash Disposal Applicable for Pacific Island Communities
(Water Resources Research Center, University of Hawaii at Manoa, 1990-08) Hindin, Ervin
The disposal of municipal solid waste is a universal societal problem. Land disposal is the most common disposal method for these wastes. This method of disposal is becoming less attractive due to sparse availability and lack of new site locations. Incineration is an alternative treatment and disposal technology. However, this technology can produce ash containing leachable hazardous substances. A study was conducted to determine the leachability of lead, cadmium, two representatives from the polycyclic aromatic hydrocarbon (PAH) group, and one member of the dioxin group from two ash fractions and an ash-basalt solidified melt. Ash from the Waipahu, Hawai'i, incinerator was classified into three fractions. One fraction was a medium-sized ash particle, predominantly bottom ash. Another fraction was a small diameter ash particle fraction, primarily fly ash. In addition, a crushed ash-basalt melt was studied. Deionized water and reconstituted seawater were used as leaching solutions. Batch and continuous-flow leaching studies revealed that lead and cadmium can be leached from the two ash fractions; however, the targeted organic compounds were not extracted. Reconstituted seawater leached less metals from the ash than deionized water. The solidified ash-basalt melt did not release metals and targeted organics into the leaching solution.

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