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HomeMy WebLinkAbout; Carlsbad municipal Golf Course; Hole 13 Drainage Issues Carlsbad Golf Course; 2000-02-11HOLE 13 DRAINAGE ISSUES CITY OF CARLSBAD GOLF COURSE Prepared for: City of Carlsbad 1635 Faraday Avenue Carlsbad, Califorma 92008 Contact: Mr. John Cahill Prepared by: P&D Environmental Services 401 West A Street, Suite 2500 San Diego, Califomia 92101 Contact: Ms. Betty Dehoney February 11,2000 February 11, 2000 P&D Consultants planners/Engineers/Architects 401 WEST "A" STREET SUITE 2500 SAN DIECO, CALIFORNIA 92101 619/232-4466 619/234-3022 FAX www.pdconsu Hants,com Mr. John Cahill CITY OF CARLSBAD - FARADAY CENTER Community Development Department 1635 Faraday Avenue Carlsbad, California 92009 SUBJECT: City of Carlsbad Municipal Golf Course project - Summary of impacts to the existing Cannon Road mitigation area Dear John, At your request and in response to the issues and concerns raised by the various permitting agencies, we have evaluated the possible impacts to the existing Cannon Road mitigation area due to the City of Carlsbad Municipal Golf Course project (specifically hole number 13). In general, we have analyzed the following: • Hydrology • Water Quality • Design alternative to the depollutant basin • Maintenance of the depollutant basin A more detailed explanation of the analysis and the conclusions reached are included in the attached study. We hope you find this information useful in you discussions with the permitting agencies. As always, please do not hesitate to contact us if you have any questions or need additionai information. Sincerely, P&D CONSULTANTS, INC. 5l A. Lee, P.E. Director of Engineering Betty Dehor>ey Director, Environmental C: USFWS (1 set of maps, 2 reports) to Julie Vanderwier/ Nancy Gilbert CDFG (1 set of maps, 2 reports) to Tamara Spear/ Bill Tippets Don Rideout (1 set of maps, 1 report) City of Carlsbad Golf Course Hole 13 Drainage Issues Hole 13 Drainage Issues HYDROLOGY Existing Condition The existing condition for the drainage basin contributing to the existing Carmon Road mitigation area is predominately characterized by rolling hills with grassland vegetation. The exception is the Faraday Avenue road-way project currently under construction by the City of Carlsbad. The overall drainage basin includes areas north, south, and east of the mitigation area. Ho^wever, an analysis of the flow entering the mitigation area is limited to the portion of the basin that flows from the north into the mitigation area, as this area will flow into the proposed depollutant basin. The areas of the drainage basin east and south of the mitigation area are excluded, as these areas will not flow into the proposed depollutant basin. The northerly portion of the overall drainage basin is divided into two sub-areas, one north and one south of Faraday Avenue. The portion of the drainage basin north of Faraday Avenue flows south and enters pipe culverts under Faraday Avenue that outlet south of the road grading. A small portion of the basin north of Faraday Avenue is part of the Faraday Avenue alignment itself. The drainage from this area enters a storm drain pipe in the roadway and outfalls on the south side of the roadway. The drainage from the area north of the roadway as well as the roadway itself, then flows south to the existing mitigation area. The total 100-year storm event flow (QlOO) entering the Cannon Road mitigation area is anticipated to be approximately 99.5 cubic feet per second (cfs). Current Proposed Condition The current proposed condition is the grading as shovm on the City of Carlsbad Municipal Golf Course project including the depollutant basin located adjacent to the northerly side of the existing Cannon Road mitigation area. The condition of the proposed drainage basin contributing to the existing Cannon Road mitigation area is a combination of rolling hills with grassland vegetation, a graded golf course, and the constructed Faraday Avenue. The analysis of the flow entering the mitigation area in the current proposed condition is limited to the area north of the mitigation area. This approach is the same as the existing condition (i.e., the analysis is for the same pre- and post-developed drainage basin). The northerly portion of the overall drainage basin is generally divided into two sub-areas, one north and one south of Faraday Avenue. The portion of the drainage basin north of Faraday Avenue flows south and enters pipe culverts under Faraday Avenue. A small portion of the basin north of Faraday Avenue is part of the Faraday Avenue alignment itself. The proposed storm drain pipes from the golf course project connect to the out-fall of the Faraday Avenue pipe culverts and convey the runoff under the golf course areas to the proposed depollutant basin. Some drainage from the golf course grading design is intercepted in smaller storm drain pipes. These smaller storm drain pipes connect to the larger storm drain pipes conveying runoff from the outfalls at Faraday Avenue to the depollutant basin. Finally, the flows exit the proposed depollutant basin via separate storm drain systems that outfall into the Cannon Road mitigation area. The total 100-year storm event flow (QlOO) entering the depollutant 0 P&D Environmental Pagel I City of Carlsbad Golf Course Hole 13 Drainage Issues basin is anticipated to be approximately 115.8 cfs. The total lOO-year storm event flow (QlOO) exiting the depollutant basin and entering the existing Carmon Road mitigation area is anticipated to be approximately 122.5 cfs. The increase in flow from (i.e., 122.5 cfs vs. 115.8 cfs) is due to the area of the mitigation area itself. The depollutant basin is not specifically designed as a detention basin. The design of the depollutant will detain flows fi'om small storm events. This runoff will be absorbed into the ground over time. Finally, the bottom of the depollutant basin is proposed to be unlined thus allowing for groundwater recharge. Water Quality P&D has attempted to obtain specific water quality data regarding the quality of nuisance water, stormwater, or other drainage. Requests for data from the Califomia Regional Water Quality Control Board (CRWQCB) was unsuccessful; however, P&D is also attempting to collect unpublished data from sources analyzing runoff on some Califomia courses. If those data are obtained (there is an issue of client confidentiality that we are attempting to address), we will supplement this analysis. The following information has been excerpted from materials collected from the intemet. Quantification of water quality of mnoff from the golf course is limited based upon our research to date. Adequate buffering and routing of surface waters, healthy turf, and careful selection of materials for use on golf courses serves to protect associated basins or waters from chemical loading. Concem with surface runoff is critical during constmction and during the "grow-in" period when the bare soil and thin turf cover makes the site most vulnerable. Golf course clearing should include installation of extensive erosion control barriers between the areas being cleared for fairways and the natural areas. These will remain in place after turf buffer strips are established and until all cleared areas have adequate turf cover to prevent erosion. Turf buffer strips of at least 15 feet have been shovm to improve water quality in runoff (Audubon Intemational, 1997). The effectiveness of turf as a buffer is related to the fibrous nature of the turf root system and the architecture of the turf canopy. Buffer strips should be fully established with a one-inch height of cut before removal of erosion barriers. As the turf matures, potential mnoff problems will diminish (Audubon Intemational, 1997). Care needs to be taken during the grow-in phase with irrigation management to prevent runoff and sediment movement into wetland areas and/or basins, and allow the buffer areas to adequately filter any possible surface nutrient/sediment movement. Controls put in place during golf course clearing should remain in place after turf buffer strips are established and until all cleared areas have adequate turf cover to prevent erosion. Turf buffer strips are an integral part of mainteriance of surface water quality (Audubon Intemational, 1997). Any runoff from turf areas will be directed into a buffer area or vegetated swale for filtration before entering any water body. Swales involve the edge contours of roughs or fairways which maximize travel distance of water, providing an additional natural filtration system S P&D Environmental Page 2 I I I I I I I I I I I I I I I I I I I City of Carlsbad Golf Course Hole 13 Drainage Issues (Audubon Intemational, 1997). Negative impacts on water quality in the wetland areas will be minimized. Relevant Studies Studies at the University of Maryland of surface runoff from turf evaluated the effects of rainfall intensity and turf seeding rate (density) on runoff initiation time, runoff rate, and sediment loss (including total movement of nitrogen and phosphates). "The research showed that surface runoff, sediment loss, and total nitrogen and phosphate movement were dramatically lower than agricultural uses" (Muirhead & Rando, 1994). Other studies at Pennsylvania State University investigated surface runoff on managed turf and concluded that managed turf grasses do not display a high potential for movement of pesticides or fertilizers (Muirhead & Rando, 1994). Measurable runoff on test sites could not be induced until test slopes were irrigated at more than twice the intensity of a 100- to 125-year storm (6 inches per hour). Even at that level, the average concentration of nutrients was well below the standard for public drinking water (Muirhead & Rando, 1994). A study on compacted clay in Georgia (Appendix A) indicated that there was some mnoff in certain conditions. As a result, Michigan State University Extension suggests to "water-in" the treatment on sensitive sites (compacted, sloping soils adjacent to surface waters). It is essential to water the application area after treatment to avoid a possible high intensity rainfall that could increase runoff, along with the possibility of carrying some fertilizer and pesticide with it (MSU Extension, 1999). - The GCSAA Foundation (Appendix B) funded a review of several golf course monitoring programs and found that no golf courses in the study produced widespread or repeated toxic effects in groundwater or surface water. Only 0.29 percent of review readings for pesticides in surface water samples were in excess of health advisory levels or maximum contaminant levels (eight courses out of 2,731). No readings indicated nitrate-nitrogen in excess of the maximum contaminant level (10 parts per million [ppm]) (GCSAA, 1997). GCSAA included 17 studies, involving 36 golf courses into the following analysis, in an effort to determme runoff contamination. The average concentration of pesticides in surface water was 0.07 to 6.8 parts per billion (ppb). In the same study, maximum allowable concentrations for aquatic organisms were exceeded in less than 1 percent (0.9 percent) of reports. Five pesticides and one metabolite exceeded their respective enforceable drinking water standards (maximum contaminant level) or their lifetime drinking water health advisory levels (HAL) at least once (GCSAA, 1997). ALTERNATIVES P&D looked at three altematives regarding the depollutant basins: • Eliminate the basin and replace with a minimal capacity graded "swale;" B P&D Environmental Page 3 City of Carlsbad Golf Course Hole 13 Drainage Issues • Retaining the basins as currently designed; and • Mechanical. The following is a discussion of the engineering and environmental feasibility of each altemative. Minimal Depollutant "Swale" This altemative would relocate and reduce the size of the depollutant basin. Generally, a swale would be constmcted southerly of Hole 13, generally in the 50-foot setback from the rough. This swale can be revegetated with a Type A mix (non-playable). This swale would intercept nuisance runoff from the course and a portion of the first flush. The capacity ofthis swale is less than the 0.5-inch rainfall event that is generally characterized in San Diego County as "first flush." The proposed mitigation would then be constmcted "at grade" with the Cannon Road mitigation site and would be "hydrologically" connected with the creek. Three issues will be discussed: engineering, enviroimiental, and regulatory constraints. Engineering. This swale would be designed to convey low flow runoff from the north along the north side of the Cannon Road mitigation area and out-fall at the dovmstream end of the existing mitigation area. The capacity of the graded unlined low flow swale would be significantly less than the currently proposed depollutant basin and storm drain pipes. However, the graded unlined low flow swale would allow for trash and debris to be intercepted during small storm events (Q2 or less). The 100-year storm event is anticipated to "top" the low flow swale and enter directly into the existing Cannon Road mitigation area; The total 100-year storm event flow (QlOO) entering the Cannon Road mitigation area is anticipated to be approximately 122.5 cfs. Finally, the bottom of the swale is proposed to be unlined thus allowing for groundwater recharge. Environmentai From an environmental perspective, this depollutant swale would accomplish the U.S. Fish and Wildlife Service's goal of creating a buffer adjacent to the new and expanded mitigation site. It does not widen the riparian corridor to the maximum extent that could occur under the original proposal. It is likely that, dependent upon the quantity of water and final grade ofthe bottom of the swale, wetland species may invade the bottom of the swale under any event. From an environmental perspective, the only negative is-that the swale is only sized to meet a minimal rainfall. Larger rainfall events will overflow directly into the creek not meeting the objectives of the NPDES program. Regulatory. There are two regulatory issues associated with this altemative. One is that the Section 401 waiver has been obtained and the second is the requirements for the NPDES permit. An initial conversation with Stacey Baczkowski ofthe CRWQCB has indicated that as long as the water flowed through a vegetated area, it did not appear to be a problem with 0 P&D Environmental Page 4 I City of Carlsbad Golf Course Hole 13 Drainage Issues the 401 certification; however, P&D has been unsuccessful in obtaining this concurrence with Greig Peters ofthe CRWQCB at this time. From another regulatory program, the City has an established NPDES program that requires that the first flush rainfall event be contained in a depollutant basis. The original basin was sized to accommodate this volume of water. The feasibility of dovmsizing the depollutant basin is uncertain from a regulatory procedural standpoint. P&D is still investigating this issue. Maintain Depollutant Basin Engineering. P&D has designed the depollutant basins to meet the NPDES criteria of containing the first flush rainfall. As discussed in the hydrology section, it is not anticipated that this basin will result in any impact to the Cannon Road mitigation site. Much of the mitigation was proposed to be hydrologically disconnected from the creek due to dual functioning as a depollutant basin. Environmental. If fhe project incorporates a 50 foot buffer from the playable area, there will be an approximate 0.75-acre reduction in available mitigation on-site. If wetlands created in any of the depollutant basins are eliminated from credit, there will be a total of 3.5 acres lost as mitigation credits, requiring additional compensation to occur off-site. Regulatory. This altemative results in the minimal conflicts with the existing Section 401 certification or NPDES permits. Additionally, concems related to opposition by the USEPA and Califomia Coastal Commission related to stormwater issues are also minimized under this scenario. Mechanical Mechanical devices include filtering systems that may include absorption "pillows" and associated holding tanks. The mechanical filtering devices would consist of fossil filter blankets incorporated into the storm drain inlets constmcted upstream of the Carmon Road mitigation area. The storm drain inlets requiring the fossil filter blankets would include the Faraday Avenue and golf course inlets. The filtering devices would have an impact on the capacity of each inlet. However, the total 100-year flow entering the storm drain systems and eventually entering the Cannon Road mitigation area would be the same as the current proposed design and the graded unlined low flow swale. The negatives associated with these devices are constant maintenance and/or replacement of these filtering systems and accommodating access to the devices. Therefore, P&D does not recommend that these devices will meet the long term objectives for this site. There is no maintenance proposed for either the current proposed design or the unlined low flow swale altemative. The filtering devices would require regular maintenance. ^ P&D Environmental Page 5 I City of Carlsbad Golf Course Hole 13 Drainage Issues REFERENCES Audubon Intemational 1997 Natural Resources Management Plan, Forest Dunes Golf Club, Grayling, Michigan. April. GCSAA 1997 Golf Course Management. November. Michigan State University Extension (MSU) 1999 Effect of Turf Management on Water Quality. November. Muirhead, Desmond & Rando, Guy L. 1994 Golf Course Development and Real Estate 0 p&D Environmental Page 6 APPENDIXA •feet of Turf Management on Water Quality http://^www.msue.msu.edii/msue/inip/modcl/42994004.html Michigan State University Extension 1994-98 Landscape CAT Alerts - 42994004 09/01/99 Effect of Turf Management on Water Quality Paul Rieke, Crop & Soil Sciences A study of the effect of turfs maintained adjacent to the Mitchell Creek on water quality in the creek has been underway since October 1992. Mitchell Creek is a small stream which empties into the east bay of Grand Traverse Bay. This is a cooperative project with the Grand Traverse County Drainage Commissioner's office, MSU Extension,,MSU turf specialists and the owners of four turf sites in the watershed. The turf sites are Ehnbrook Golf Course, Mitchell Creek Golf Course, Traverse City East Junior High School and Ball World (a softball complex). The main emphasis in this project is on effects of fertilization, particularly with nitrogen and phosphorus. Data to date mdicate there are very low levels of nitrates and phosphorus in the stream as it passes through the golf courses with no increase of either nutrient. Soil tests for these nutrients suggest there is no appreciable downward movement of either nutrient in the soil profile. Nitrates have been tested in the 0-6, 6-12 and 12-18 inch depths on greens and fairways. Phosphorus soil tests have been taken in the 0-3, 3-6 and 6-9 inch depths. The greens tend to test high for phosphorus in the 0-3 inch depth with intermediate levels in the 3-6 inch depth and very low levels at the 6-9 inch depth. At the two golf courses, there is a layer of 2-3 inches of topdressing sand applied over the past several years. Some of the higher level of phosphorus at the 3-6 inch depth likely occurs because that was the original top layer which had received phosphorus fertilization before the sand topdressing program began. Suction lysimeters placed adjacent to three fairways on each course yielded soil water samples which had very low levels of both nitrates and phosphorus. The bottom line is that there little to no effect of the fertilizer programs on these turf sites on the water quality in Mitchell Creek. The one recommendation made for change in their fertilization programs was for the turfs which had high phosphorus soil tests, use of a fertilizer which contains no phosphorus is recommended. This limits the choices available for the turf manager as only a few fertilizers contain no phosphorus. Turf managers need to work with their fertilizer dealers to fmd the appropriate fertilizers. The results of this project to date are consistent with reports from other parts of the country. The U. S. Golf Association has been supporting environmentally-oriented lof 3, ' 2/9/00 4:17 PM ffect of Turf Management on Water Quality research at several universities for the past three years. Reports on this research were made a week ago. For established turfs with good fertility programs there was • very little nitrate found in drainage water. These studies utilized lysimeters so all drainage water could be collected. The first year of study on sites where soils were disturbed there was some nitrate leached, but after that there was little problem. A study at Penn State mdicated there was essentially no pesticide or fertilizer runoff from their turf site. /Another study in Georgia on a compacted clay suggested there was some runoff under certain conditions. As a result, we suggest that on sensitive sites (compacted, sloping soils adjacent to surface waters) it is best to "water-in" the freatment after application. This means right after a fertilizer application. Do not wait for a potential rainfall to accomplish this as a high intensity rain could cause runoff and increase the probability of carrying some fertilizer or pesticide with it. For herbicide freatments, wait until 6-8 hours of sunlight before irrigating. This water application will tend to move the chemical into the thatch and rootzone so there will be little potential for movement with any runoff water. There was some leaching of dicamba detected in some studies and very small amounts of 2,4-D in one study. We have known dicamba is quite water soluble. So on sensitive • sites with shallow water tables, it may be best to find an altemative to dicamba. So the bottom line seems to be that with established turfs there is little problem with turf maintenance on water quality if reasonable practices are followed. Turf managers must be aware of the unique conditions which exist on a turf site that should be considered in planning a chemical management program. This applies not only to golf course superintendents, but also to lawn care company operators and other grounds rhanagers. More next week on guidelines for maintaining turf adjacent to surface waters. http://virww.msue.msu.edu/msue/imp/modcl/42994004.html Go To Top of File Michigan State Universitv Extension Home Page Main Page for this Data Base Landscape CAT Home Page This information is for educational purposes only. References to commercial products or trade names does not imply endorsement by MSU Extension or bias against those not mentioned. Tbis information becomes piiblic property upon publication and may be printed verbatim with credit to MSU Extension. Reprinting cannot be used to endorse or advertiseja commercial product or company. This file was generated from data base Cl on 11/02/99. Data base Cl was last revised on 09/01/99. For more information about this data base or its contents please contact catalerKaHnsue.msu.edii . Please read our disclaimer for important information about using our site. 2 of 3 2/9/00 4:17 PM APPENDIX B CM November 1997 - Water pollution minimal from monitored courses http://w-ww.gcsaa.Org/gcm/gcm_archive/1997/nov97/l lwater.html Water pollution minimal from monitored courses GCS AA's Golf Course Water Quality Sttidy finds little chemical pollution from monitored courses. Stuart Cohen, Ph.D., Ameha Svrjcek, Tom Durborow and N. LaJan Barnes Golf courses are regarded by some as potential sources of water pollution, and many have been closely monitored since the late 1980s. These monitoring studies rarely receive publicity, however, nor are they usually compared in order to identify trends in water quality as it is affected by golf courses. To better understand the potential environmental effects of golf courses. The GCSAA Foundation funded a review of several golf course monitoring programs. Minimal water contamination was found in GCSAA's golf course water quality study, a review of several monitored courses, including Pebble Beach Golf Links, (Photo courtesy of Pebble Beach Co,) or surface water during This review revealed that none of the golf courses in the study produced widespread or repeated toxic effects in groundwater the periods studied: Just 0.07 percent of readings for pesticides in groundwater samples were in excess of health advisory levels or maximum contaminant levels (nine out of 12,101). Only 0.29 percent of readings for pesticides in surface water samples were in excess of health advisory levels or maximum contaminant levels (eight out of 2,731). In surface water samples, there were no readings of nitrate-nitrogen in excess of the maximum contaminant level (10 ppm). Thirty-one of 849 (3.6 percent) groundwater samples exceeded 10 ppm of nitrate-nitrogen. History of monitoring U.S. researchers, regulators and pesticide companies began to focus on agricultural pesticides in surface water and groundwater in the late 1970s and early '80s (16,38,41,48,49,52). Since then, studies, papers and reports have proliferated. In 1992, the EPA released a compilation of 150 studies of pesticides in groundwater (18). A recent book (2) summarizes more than 300 groundwater studies. There has also been intensive interest recently in agricultural pesticides iii surface water (42,45). 1 of 9 2/9/00 4:49 PM CM November 1997 - Water pollution minimal from monitored courses http;//www.gcsaa.org/gcna/gcm_archive/1997/nov97/l lwater.html It's usually not appropriate to extrapolate results from agricultural monitoring studies to golf courses because ofthe different management practices, plant canopies, surface mat (thatch) and f obt densities involved. In addition, the volume of runoff water from managed turf is usually less, and eroded sediments are significantly reduced in turf compared with row crop agriculture (51). A groundwater monitoring study of four golf courses on Cape Cod found several pesticide and nitrate detections but no significant impacts (14,15).. In a 1987-1990 national survey of drinking wells, the EPA found greater amounts of tetrachlorophthalic acids (metabolites of the herbicide dacthal) in multistate regions where there were many golf courses. But a smaller-scale correlation analysis linking those results to golf course use was not possible. C5CSAA Iras rec.eiyeid niimefousvf; requests for ihfQrination ;oh:the.,5:-^;?-:''"?v 'Impactpfl'if golf courses .oH'^vateri-v'/V'^ qual ity 2jThe - assbciatioh's need ifdir .i^ .:siLicHi:ii,^%..:^ ihfbrifnationv, prompted , TheGiCSAAt ^uhdaltibn; r to ifund^thiis • Many golf courses around the country built since the late '80s have been required to monitor groundwater and surface -water quality as a result of permit conditions. These studies are rarely published in peer-reviewed literature, and they are usually not publicized at all. GCSAA has received numerous requests for information on the impact of golf courses on water quality. The association's need for such information prompted The GCSAA Foundation to fund this study. Discovery and review of field studies Results of surface water and groundwater studies conducted on golf courses throughout the United States were solicited in an effort tO' gather a broad range of coverage and minimize biased conclusions. Information was publicly requested, and was followed by articles in GCSAA's Newsline. In addition, requests went to all 50 state environmental water quality regulatory agencies and several EPA regional offices. As part ofthis study, information about 13 studies obtained in a preliminary review of this subject (13) was updated. . Each study underwent a preliminary review for specific acceptance criteria. We contacted authorities to ensure that adequate quality control measures were followed by the participating laboratories. All numerical data from the accepted studies were then entered into a database, and approximately 10 to 20 percent of the data were checked for completeness and accuracy in an in-house quality-control review. The United States was divided into broad regions based on hydrology, hydrogeology and climate to help organize the data collection. There are 20 surface water resource regions of the United States, as classified by the U.S. Water Resources Council (46); 12 major turfgrass climatic zones (5,47); and 13 groundwater regions (29). We classified the monitoring studies according to these geographic references. We reviewed 19 studies, involving 40 golf courses, for this paper. Seventeen studies (36 golf courses) passed the review criteria and were included in the statistical analyses. All but one of the 36 courses were located in the United States. (One study was done on Prince Edward Island, Canada.) Data from the other two studies ~ in Guam and Japan ~ were not added to the database. We assembled a list of the 134 pesticides, metabolites and solvents that were analyzed in one or more of the studies. We attempted to exclude pesticides that would theoretically never be used at a golf course either on turf, in ponds or in related areas. However, when in doubt, the pesticide was included. This is because pesticide registrations are constantly changing. For example, most people would associate past use of the insecticide chlordane with field crops and with termite control in buildings — before its use on golf courses. However, chlordane was used to control mole crickets 2 of 9 2/9/00 4:49 PM |CM November 1997 - Water pollution minunal from monitored coiirses ' http://-www.gcsaa.org/gcm/gcm_archive/r997/nov97/l lwater.html and crabgrass at golf courses in the early '70s. Further, when pesticide regisfrations are canceled, use of existing stocks may continue for several years. Statistical analyses After the preliminary review, data were entered into Paradox database soflware (Borland, version 5.0). All data underwent a quality-control check for accuracy in which 10 to 20 percent of data entries in each database were reviewed after entry. Statistical analyses were conducted in Paradox and StatMost software. Since studies were collected from a variety of sources, methods for reporting the data and conducting statistical analyses varied and were not subject to our initial acceptance criteria. This complicated the selection of appropriate statistical procedures to apply. For example, attempts were made to obtain information for each individual sampling event. In three reports, however, mean values for pesticides or nitrate-nitrogen were reported. In those cases, the mean values were used. There were limitations of the data. First, the study areas were not selected with randomization, whereby ali golf courses in the country or in a region have equal probability of being selected for a monitoring study. Therefore, the number and type of valid statistical analyses and extrapolations that could be done were also limited. These results reflect only the conditions at the golf courses studied and are not meant to be national estimates for golf course impacts on water quality. The second limitation is more of a problem in data interpretation. A large fraction of the data entries are "non-detects" (NDs), which means the substance analyzed was not detected. But it is not clear how these data should be entered when calculations are done. Should non-detect equal zero? Should it equal the detection limit? Should it equal a value between zero and the detection limit? The EPA stated in recent guidance (17) that "substitution methods" are suitable for data sets in which less than 15 percent of the values are non-detects (ND). In this approach, a specific number is substituted for each non-detect. The standard practice, which the EPA endorses, is to substitute half the detection limit for all non-detect values. We have adopted the EPA approach for the nitrate-nitrogen in groundwater data set, where the non-detect rate was less than 15 percent. We could find no practical guidance for characterizing a data set in which,more than 90 percent of the entries are non-detects, which is the case for the surface water database and groundwater database entries for pesticides and related chemicals. Therefore, we present a range of means: the lower end of the range assumes non-detect equals zero, and the upper end of the range assumes non-detect equals the detection limit. By doing this, we are stating that we do not know the tme answer, but we know it lies somewhere witiiin the stated range. jM , Overview of results viiBiMi^SiS The database includes 16,587 entries. Each entry is one analysis for a S B B S ^ t single chemical in one sample. Results from groundwater studies dominate the database. The studies we evaluated spanned 12 groundwater/climate-zone combinations and 10 surface water/climate-zone combinations. It is important to note that 13 pesticide and volatile organic entries were deleted from the database because they were almost certainly not used in association with golf courses. They include aldicarb, alachlor, pentachlorophenol, dinoseb, bromoform and • chloromethane. This had the net effect of decreasing the database by more than 100 entries. Surface water ~ pesticides •Few pesticides detected - siirface water Of the 31 pesticides and metabolites detected 3 of 9 2/9/00 4:49 PM I;M November 1997 - Water pollution minimal from monitored coiirses http://'www.gcsaa.org/gcm/gcm_archive/1997/nov97/l lwater.html in surface water, nine chemicals exceeded maximum allowable concentrations (MACs) for aquatic organisms for one or more samplings. Maximum allowable concentrations were calculated for all but three pesticides that had available EPA ambient water quality criteria. Thirteen (including two metabolites) were maximum allowable concenfrations calculated or estimated by the Vermont Department of Environmental Conservation as part of its toxic discharge control sttategy. These maximum allowable concenttations are primarily based on methodologies developed by the EPA to derive numerical water quality criteria for aquatic species when large amounts of data are available. The remaining 15 pesticide MACs were calculated using 1/10 the LC50 or EC50 of the most sensitive freshwater invertebrate or fish species. The toxicity data reviewed were taken from EPA pesticide fact sheets and the EPA pesticide ecotoxicity database, as well as other resources (22). The LC50 (lethal concentration) is the concenttation in water of a substance that is lethal to 50 percent ofthe test population in a carefully controlled study environment. The EC50 is similar to the LC50 except that the endpoint is some effect other than death. Such values describe a chemical's toxicity. For example, a pesticide with an LC50 less than 100 ppb is considered very highly toxic, and therefore a very low dose is potentially lethal to the test organism. Aquatic toxicity categories for LC50 or EC50 values were established by the EPA and can be used to qualitatively describe ranges of, aquatic toxicity. The nine pesticides that were reported in excess of maximum allowable concentrations for aquatic organisms were chlorothalonil (one report), chlorpyrifos (nine reports), diazinon (eight reports), ethoprop (one report), fenamiphos sulfone (one report), fenamiphos sulfoxide (two reports), isofenphos (one report), malathion (one report) and simazine (one report). All nine chlorpyrifos detections (0.1 to 0.3 ppb) were from one small-scale study that measured mnoff from a golf course following an application of chlorpyrifos and irrigation, and they reflect several storm events. It should be noted that diazinon use on golf courses has been banned since the 1988-1990 time period; therefore most of the diazinon detections may be due to nearby lawn use. Overall, maximum allowable concentrations for aquatic organisms were exceeded in less than 1 percent (0.9 percent) of reports - or 0.6 percent if the diazinon results are excluded. Five pesticides and one metabolite exceeded their respective enforceable drinking water standards (maximum contaminant level) or their lifetime drinking water health advisory level (HAL) at least once. The average concentration of pesticides in surface water was 0.07 to 6.8 parts per billion. As explained, the lower end of the range assumes a non-detect equals zero, and the upper end of the range assumes non-detect equals the detection limit, whatever it may be, for the particular pesticide in the particular study. Surface water - nitrates There were only 201 non-detects in a surface water database of 906 entries for nitrates. The winsorized mean was 0.3 ± 0.3 parts per million, and the upper 90th percentile was 0.72 ppm in the winsorized analysis and 1.47 ppm when all data were used. The median • was 0.21 ppm when the data were winsorized and 0.38 ppm (very similar) when all data were used. There were no detections exceeding the 10 ppm legal maximum contaminant level in any of the surface water samples. Groundwater ~ pesticides •Few pesticides detected - ground water There were 103 monitoring points (wells, lof 9 2/9/00 4:49 PM CM November 1997 - Water pollution minimal from monitored courses http://www.gcsaa.Org/gcm/gcm_archive/1997/nov97/l lwater.html lysimeters, imderdrains) in these studies, and 52 of them had at least one pesticide detection. Most, if not all, monitoring points were sampled more than once, and most studies lasted more than one year. The organics/groimdwater database includes analyses for approximately 115 chemicals as part of a 12,101-entry database in this category. No volatile organic compounds were detected in the studies. There were 21 pesticides/ metabolites detected among 160 total detections (1.3 percent of the database entries). Only nine detections ~ 0.07 percent ~ exceeded a "maximum contaminant level" (MCL) or "health advisory level" (HAL). Most of the excesses were from studies in Florida. The average concentration of pesticides in groundwater was 0.09 to 3.6 ppb, depending on whether non-detects were defined as zero or as the detection limits. The 95th percentile concentration was between zero ppb and 10 ppb. Groundwater - nitrates Only 81 of 849 database entries were non-detects for nitrates, therefore the substitution approach was used whereby each non-detect was substituted by one-half of the nitrate-nitrogen detection limit for the particular study. The average nitrate-nitrogen concentration was 1.6 ppm and 0.3 ppm when computed with the raw data and the log-transformed data, respectively. The median was 0.45 ppm. Impacts and trends It is important to note that none of the reports we reviewed concluded that turf management was causing significant impacts on groundwater quality. Most researchers concluded that no significant impacts were observed. A few stated, however, that more data are needed before definitive conclusions could be reached. A comparison of pesticides in surface water with pesticides in groundwater produced a different conclusion than we had expected. We expected higher detection frequencies in the surface water database, but detection frequencies between surface and groundwater were similar. Specifically, the frequencies of monitoring points with at least one detection was 50 percent and 54 percent for groundwater and surface water studies, respectively. Also, 6 percent of surface water monitoring sites and 7 percent of groundwater sites had at least one report of a pesticide or metabolite in excess of a HAL or MCL. The percent of database entries that exceeded HALs or MCLs for groundwater and surface water were 0.07 percent and 0.29 percent, respectively. However, the use of chronic HALs or MCLs to evaluate short-term surface water concentrations is an overly conservative risk assessment practice. This is because the HALs and MCLs assume daily exposure to contaminated water for a lifetime. Surface water contamination by pesticides, ifit occurs, is sporadic. Maximum allowable concentrations were exceeded in 0.9 percent of surface water samples (0.6 percent if diazinon is excluded). Only 1.3 percent (160 out of 12,101) of the groundwater organics database had detections, whereas the detection rate in the surface water organics database was 5.2 percent (141 out of 2,731). Impact of other land uses Some chemical detections in the database may be the result of nearby or prior land uses. For example: • Eight readings in excess of maximum allowable concentrations were due to diazinon. Diazinon use on golf courses was phased out between 1988 and 1990. Its field dissipation half-Ufe is approximately one month, depending on the site. Most of these studies were done between 1990 and 1995, long after most of 9 2/9/00 4:49 PM !:;M November 1997 - Water pollution minimal from monitored courses http://www.gcsaa.Org/gcm/gcm_archive/1997/nov97/l lwater.html diazinon residues would have degraded. The probability is low that these results are caused by golf course use. However, home la-wn use is still allowed, and golf courses are frequently part of housing developments. Thus it is likely that at least some of these results, if not all of them, can be attributed to home lavm use. • Similarly, 2,4-D has been detected at two of the golf courses in this study — Caves Valley and Bayberry Hills ~ at time periods prior to any application to the golf courses. This herbicide is used widely in agriculture, on home lavms, and in rights-of-way applications. • When the Queenstown golf course was constmcted, several of the groundwater samples exceeded the federally mandated 10 ppm nitrate-nitrogen maximum contaminant level. These concenttations have declined over time. The site had been farmland, and nearby land is also farmed, so much of the nitrate probably originated from agriculture. • Finally, the authors of this report have seen golf courses on Long Island and elsewhere blamed for frequent detections ofthe principal metabolite of dacthal. Dacthal was used on golf courses, but it has also had major agriculture and home lav/n uses. Golf course turf area is less than 1 percent of harvested cropland area (12). Thus most of the country's dacthal metabolite detections probably originated from sources other than golf courses. It should not automatically be assumed that any pesticide or nitrate detected at golf course sites was caused by golf course management. It is important to consider prior and adjacent land use and pesticide use, as well as surface water and ground-water hydrology, as part of an appropriate analysis. Comparisons with other studies Pesticides in groundwater The EPA has conducted two comprehensive national studies of pesticides in groundwater. Its statistically based national pesticide survey is not directly relevant because it was a true national study with representative wells from all 50 states (19). More relevant to this study was the EPA's compilation of resuhs from 150 studies of pesticides in groundwater (18). The studies focused mostly on agricultural pesticides. The number of wells with detections was 24 percent in the EPA study and 50 percent in the GCSAA study. However, wells with detections exceeding health advisory levels or federally mandated maximum contaminant levels were 14 percent in the EPA review and only 7 percent in this review. It should be noted that most of the wells monitored in the current study were shallow wells or underdrains installed in or adjacent to managed turf areas. The EPA database contains a significant fraction of deeper drinking water wells that may be more distant from the treatment areas than the 0 to 40 feet typical of the golf course studies. Nitrates in groundwater In a 1993 review of approximately 90 papers relevant to groundwater contamination by nitrates (40), breaches of "maximum contaminant levels" from 13 large-scale surveys ranged from 3 percent to 36 percent, and most exceeded 10 percent. As reported above, only 4 percent (30 out of 849) of the groundwater database entries in the GCSAA review exceeded the 10 ppm MCL for nitrate in drinking water. Ten percent (seven out of 72) of the groundwater sampling locations had at least one reading in excess ofthe mandated maximum contaminant level. However, most of the nitrate excesses appeared to be the result of prior agricultural use. Pesticides in surface water Agricultural herbicide monitoring in the Midwest typically has a 50 to 100 percent detection rate, and readings in excess of federally mandated lifetime maximum contaminant levels are often greater than 20 percent (45,11). The results of our review compare favorably with these detection frequencies. Just 5.2 percent of database entries "6 of 9 2/9/00 4:49 PM ;M November 1997 - Water pollution minimal from monitored courses http://www.gcsaa.Org/gcm/gcm_archive/1997/nov97/l lwater.html indicated the presence of pesticides. Fifty-four percent of surface water sampling sites had pesticides present at some time, but just 0.29 percent of the samples analyzed for pesticides exceeded lifetime health advisory levels or maximum contaminant levels. Nitrates in surface water Although no comparable database could be found for nitrate levels in surface water, it is the experience of the senior author that the concentrations and detection frequencies seen in this review are similar to results from general surface water quality monitoring at sites with a variety of land uses. Conclusions This detailed review of 17 water quality studies of 36 golf courses, separately and together, indicates that widespread or repeated water quality impacts by golf courses are not occurring in the areas studied. None ofthe authors of the individual studies concluded that toxicologically significant impacts were observed. The percent of individual pesticide database entries that exceeded health advisory levels or maximum contaminant levels for groundwater and surface water were 0.07 percent and 0.29 percent, respectively. In surface water samples, there were no readings of nitrate-nitrogen in excess ofthe maximum contaminant level (10 ppm) and only 31 of 849 (3.6 percent) groundwater samples exceeded 10 ppm of nitrate-nitrogen. These results indicate that although nitrates and pesticides were detected in surface water and groundwater samples from the golf courses in this study, their infrequency and low concentration pose a very limited threat of environmental pollution. Literature cited 1. Apogee Research, Horseley Witten Hegemann Inc. 1996. Water Quality Report No. 21 ~ Queenstown, Maryland. Apogee Research, Bethesda, Md. and Horseley Witten Hegemann Inc., Washington, D.C, 2. Barbash, J.E., and E.A. Resek. 1996. Pesticides in groundwater, Ann Arbor Press, Chelsea, Mich. 3. Barten, J., Hennepin Parks and Minnesota GCSA. 1992. Baker National Golf Course leachate study. Suburban Hennepin Regional Park Disfrict, Plymouth, Minn. 4. Barten, J., and Hennepin Parks. 1994. Quantity and quality of runoff from four golf courses in the Twin Cities metropolitan area. Suburban Hennepin Regional Park District, Plymouth, Minn. 5. Beard, J.B. 1979. How to have a beautiful lawn. Beard Books, College Station, Texas. 6. Beard, J.B. 1982. Turf management for golf courses, The Macmillan Co., New York. 7. Brock, R., and A. Kam. 1994. Waikoloa anchialine pond program. University of Hawaii, Honolulu. 8. Camp Dresser, and McKee. 1992. Sarasota Bay national estuary program and non-point source loading assessment. CDM, Sarasota, Fla. 9. Carpenter, P., and J. Toal. 1996. Storm water monitoring of watersheds including golf courses on the Monterey Peninsula. Kiiuietic Laboratories Inc., Santa Cruz, Calif 10. Chesapeake Environmental Management. 1996. Environmental monitoring program for Caves Valley Golf Club, CEM, Belair, Md. 11. Cohen, B., R. Wiles and E. Bondoc. 1995. Weed killer by the glass: A citizen's tap water monitormg project in 29 cities. Environmental Working Group, Washington, D.C. 12. Cohen, S.Z. 1995. Agriculture and the golf course industry: An exploration of pesticide use. Golf Course Management 63(5):96-104. 13. Cohen, S.Z., and T.E. Durborow. 1994. Watershed findings: pesticides test well. Golf Course News 5(2)1,24-27. 14. Cohen, S.Z., S. Nickerson, R. Maxey, A. Dupuy and J.A. Senita. 1990. A groundwater monitoring study for pesticides and nifrates associated with golf courses on Cape Cod. Grounci Water Mon. Rev. 10(0:160-173. 15. Cohen, S.Z. 1990. The Cape Cod study. Go/fCouz-ie A'/anage/we/ii'58(2)26-44. 16. Cohen, S.Z., S.M. Creeger, R.L. Carsel and CG. Enfield. 1984. Potential for pesticide contamination of groundwater resulting from agricultural use. p. 259, 297-325. In: R.F. Krueger and J.N. Seiber (eds.). Treatment and disposal of pesticide wastes. Am. Chemical Soc. Symposium Series, Washington, D.C. 17. Environmental Protection Agency. 1996. Guidance for data quality assessment: practical methods for data analysis. USEPA QA/G-9 QA96 Version, EPA/600/R-96/084. U.S. Gov. Print. Office, Washington D.C. 18. Environmental Protection Agency. 1992a. Pesticides in groundwater database: a compilation of 7 of 9 2/9/00 4:49 PM DM November 1997 - Water pollution minimal from monitored courses http://www.gcsaa.Org/gcm/gcm_archive/1997/nov97/l lwater.html monitoring studies: 1971-1991. EPA 734-12-92-001. U.S. Gov. Print. Office. Washington, D.C. 19. Environmental Protection Agency. 1992b. Another look: national survey of pesticides in drinking water wells-Phase II report. EPA 579/09-91-020. U.S. Gov. Print. Office. Washington, D.C. 20. Evans-Hamilton Inc. and Dalton, Olmsted & Fuglevand Inc. 1990. The Falls Country Club surface water and groundwater monitoring plan. Evans-Hamilton Inc., Seattle, Wash., and Dalton, Olmsted & Fuglevand Inc., Bothell, Wash. 21. Evans-Hamilton Inc. and Rensel Associates Inc. 1996. Reports from Echo Falls Golf and Coimtry Club surface water quality monitoring. Evans-Hamilton Inc., Seattle, Wash., and Rensel Associates hic, Arlington, Wash. 22. Farm chemicals handbook. 1997. Meister Publishing Co., Willoughby, Ohio. 23. Felton, G.K., and A.J. Powell Jr. 1993. Turfgrass chemicals exiting a well-managed golf course. Univ. of Kentucky, Lexington. 24. Fern, J., and C. Nothwanger. 1996. Singing Hills Country Club water quality reports. Applied Consultants, San Diego, Calif. 25. Floh, S.B,, L.A. Mahoney, J.C. Batey and D.M. Petroff 1996. Evaluation of the use of substitution methods to represent non-detect data. In: Keith Hoddinott (ed.), Superfund risk assessment in soil contammation studies: 2nd volume, ASTM STP 1264. Am. Soc. for Testing and Materials. 26. Gibbons, R.D. 1994. Statistical methods for groundwater monitoring. Wiley and Sons, New York. 27. Greenhalgh, T., and B. Moore. 1991. Palm Beach golf course study. Florida Dept. of Environmental Regulation, Tallahassee, Fla. 28. Guam EPA. 1992. Guam Intemational Country Club, groundwater quality monitoring program review. Guam. 29. Heath, R.C. 1982. Classifications of groundwater regions of the United States. Groundwater 20(4). 30. Heath, R.C. 1984. Ground-water regions ofthe United States. U.S. Geological Survey Water Supply Paper 2242. U.S, Gov Print. Office, Washington, D.C. 31. Helsel, D.R. 1990. Less than obvious: Statistical treatment of data below the detection limit. Environmental Sci. Technology 2A{\2y.\166-\ll A. 32. Horst, G.L., P,J. Shea, N. Christians, D.R. Miller, C. Stuefer-Powell and S.K. Starrett. 1996. Pesticide dissipation under golf course fairway conditions. Crop Sci. 36(2):362-370. 33. Inst, of Wildlife and Environmental Toxicology at Clemson University. 1993. Environmental sensitive techniques in golf course management: a model study at the Ocean Course, Kiawah Island, S.C. Clemson University, Pendleton, S.C. 34. Kaysak P., E. Rzemien and R. Newport. 1990-1995. Caves Valley Golf Club environmental monitoring program. Versar Inc., Columbia, Md. 35. Kenna, M.P. 1995. What happens to pesticides applied to golf courses? USGA Green Section Record, 33:1-9. 36. Miles, C.J., G. Leong and S. Dollar. 1990. Pesticides in marine sedunents associated with golf course runoff at Ka'anapali, Hawaii. Univ. of Hawaii, Honolulu. 37. Minoura, K., S. Ohba, S. Washioka and 0. Yamada. 1994. Environmental study on water inside/around golf courses in Japan. Abstract/Poster No. 113, Eighth lUPAC Intemal Congress of Pesticide Chemistry Book of Aijstracts. lUPAC/Am. Chem. Soc, Washington, D.C. 38. Peoples, S.A,, K.T. Maddy, W. Cusick, T. Jackson, C. Cooper and A.S. Frederickson. 1980. A study of samples of well water collected from selected areas in Califomia to determine the presence of DBCP and certain other pesticide residues. Bull. Environmental Contamination and roxico/ogy24(4):611-618. 39. Pierce, N., B. Raymond. 1997. The Links at Crowbush Cove water quality data. Prince Edward Island Dept. of Environment, PEI, Canada. 40. Spalding, R.F., and M.E. Exner. 1993. Occurrence of Nitrate in Groundwater - A Review. J. Environmental Quality 22:392-402. 41. Spalding, R.F., G.A. Junk and J.J. Richard. 1980. Pesticides in groundwater beneath hrigated farmland m Nebraska, August 1978. J. Pesticide Monitoring 14(2):70-73. 42. Stamer, J.K. 1996. Water supply: implications of herbicide sampling. J. Am. Water Works Assoc. Feb., p. 76-85. 43. Swancar, A. 1996. Water quality, pesticide occurrence, and effects of irrigation with reclaimed water at golf courses in Florida. USGS, Tampa, FL. 44. Tessier, D., and E. Nash. 1996. A summary of Bayberry Hills Golf Course groundwater monitoring program December 1988 to March 1996. West Yarmouth, Mass. 45. Thurman, E.M., D.A. Goolsby, M.T. Meyer. 1992. A reconnaissance study of herbicides and their metabolites in surface water of the midwestem United States using immunoassay and gas chromatography/mass spectrometry. Environmental Sci. Technology, 26:2440-2447. 46. U.S. Water Resources Council. 1968. The nation's water resources, p. 808. In: van der Leeden, F., F.L. Troise and D K. Todd (eds), 1991, The Water Encyclopedia. 2nd ed. Lewis Publishers, Chelsea, Mich. 47. van der Leeden, F., F.L. Troise and D.K. Todd. 1991. The Water Encyclopedia. 2nd ed. Lewis • Publishers, Chelsea, Mich. 48. Wauchope, R.D. 1978. The pesticide content of surface water draining from agricultural fields ~ a review. J. Environmental Quality 7(4):459-472. 49. Wauchope, R.D., and R.A. Leonard. 1980. Maximum pesticide concenfrations in agricultural mnoff: a semi-empirical prediction formula. J. Environmental Quality 9:655-672. 50. Water Resources Institute of Grand Valley State University. 1995. Water quality assessment and 'of 9 • 2/9/00 4:49 PM |CM November 1997 - Water pollution minimal from monitored courses http://www.gcsaa.Org/gcm/gcm_archive/1997/nov97/l lwater.html recommendations for the Meadows Golf Club. Grand Valley State Univ., Allendale, Mich. 51. Welterlen, M.S., CM. Gross, J.S. Angle and R.L. Hill. 1989. Surface mnoff from turf. p. 153-160 In: A.R. Leslie and R.L. Metcalf (eds.). Integrated Pest Management for Turfgrass and Ornamentals. 52. Zaki, M.H., D. Moran and D. Hartis. 1982. Pesticides in groundwater: the aldicarb story in Suffolk County, N.Y. Am. J. Public Health, 72:1391-1395. Stuart Cohen, Ph.D., is ah environmental chemist, a certified groundwater professional, and is president of Envfronmental & Turf Services Inc. of Wheaton, Md. Amelia Svrjcek is an environmental scientist. LaJan Barnes is a registered geologist with a master's degree in hydrogeology. Tom Durborow is a specialist in surface water studies. All were employed by Envfronmental & Turf Services Inc. during this research project. 9 of 9 2/9/00 4:49 PM