Grantee Research Project Results
2002 Progress Report: The Impact of Lawn Care Practices on Aquatic Ecosystems in Suburban Watersheds.
EPA Grant Number: R828007Title: The Impact of Lawn Care Practices on Aquatic Ecosystems in Suburban Watersheds.
Investigators: Armbrust, Kevin L. , Williams, James B. , Black, Marsha C. , Keeler, Andrew G. , Meyer, Judith L. , West, Dee , Shuman, Larry , Noblet, Raymond , Gragson, Ted
Institution: University of Georgia , Peachtree City Developmental Services , Mississippi State University , Alpharetta Environmental Services
Current Institution: University of Georgia , Alpharetta Environmental Services , Mississippi State University , Peachtree City Developmental Services
EPA Project Officer: Packard, Benjamin H
Project Period: March 1, 2000 through February 28, 2003
Project Period Covered by this Report: March 1, 2002 through February 28, 2003
Project Amount: $893,849
RFA: Water and Watersheds (1999) RFA Text | Recipients Lists
Research Category: Watersheds , Water
Objective:
The main objective of this research project is to determine whether homeowner beliefs, values, and socioeconomic status will determine loads and ecological impacts on turf care chemicals (pesticides and nutrients) in aquatic ecosystems in suburbanized watersheds. The specific objectives of this research project are to: (1) measure loading to streams and temporal trends in concentrations of turf care products and biological indicators of stream ecosystem health in creeks receiving storm water drainage from residential neighborhoods of different socioeconomic status; and (2) compare the cultural models of lawn and lawn care held by “experts” and “homeowners” to determine their points of commonality and divergence, and establish the systematic nature of internal and contrastive variation.
Progress Summary:
Objective 1. In support of the first objective mentioned above, the activities and accomplishments focused on monitoring water and sediment for pesticides, nutrients, metals, and biological impacts in suburban and reference streams.
The purpose of this year’s work was to finish collecting and analyzing water and sediment collected from residential streams in Peachtree City and a stream that drains a golf course in a metropolitan Atlanta suburb. All proposed work for the grant has been completed. Monthly samples of water and sediment were collected from streams, and water from tile drains was collected based on either rainstorm or “green flushing” events. Water collected from fairway runoff was based on rainstorm events. Samples from water and sediment were analyzed for commonly used turf pesticides, although pesticides monitored in tile drainage and fairway runoff were based on use records maintained by the golf course. In residential stream sediment, chlorpyrifos and dithiopyr were the most commonly detected pesticides, and also were found in sediment at the highest concentration. In water samples, these same chemicals also were frequently detected as were chlorothalonil and its main degradation product, 4-hydroxy-2,5,6-trichloroisophthalonitrile (hydroxychlorothalonil). Prodiamine, pendimethalin, and diazinon also were detected, but at a lower frequency. Generally, pesticidal loadings from neighborhoods were not so much associated with level of income as to the amount of impervious surface and size of the drainage area within the neighborhood. The pre-emergent herbicides, oxadiazon and dithiopyr, were applied to fairways respectively in the spring and fall. The fungicides, chlorothalonil and flutolanil, were the most heavily applied chemicals to the greens. Hydroxychlorothalonil commonly was detected at low ppm concentrations, but was detected at high ppt concentrations in a stream directly receiving this drainage indicating significant dilution of tile drainage was occurring. In the cases of both tile drainage and fairway runoff, the highest concentrations of pesticides in water occurred in events immediately following application of the chemicals. Levels in water were greatly reduced in subsequent events occurring after application.
Analyses of water quality are essentially complete to date starting in July 2000, and ending in March 2003, totaling 33 dates at 6 sites. Water quality measurements are for NO3-N, NH4-N, soluble P, turbidity, total suspended solids (TSS), and dissolved organic carbon (DOC). Four storm events were sampled in the spring of 2002 at storm drains and sample analyses were for NO3-N, NH4-N, and soluble P. This sampling was conducted using ISCO samplers set at one sample every 15 minutes during the event. Data are for each sample taken. The pattern for nitrate-N was that of being low in the fall and winter months (< 0.2 mg/L) (with the exception of October 2000) and higher in the summer months (0.3 to 0.4 mg/L). The ammonium-N concentrations followed that same pattern for 2001, but in 2002, the data fluctuated with no clear pattern. There were no discernable differences among sites for the ammonium-N data, but for the nitrate-N data, the Cherry Branch site usually was the lowest, and the Oak Newell site often was the highest. Soluble phosphate-P concentrations were low during the fall and winter of 2001-2002 and increased during the summer of 2002. Turbidity values generally were low from September 2002–July 2003 (< 10 nephelometric turbidity units [NTU]). There were peaks for all sites for turbidity in October 2002. The TSS data were well correlated with the turbidity measurements. The Crabapple Lane and Keg Creek sites often were found to be higher in turbidity values than the other sites. The DOC values were very consistent from one sampling to another, usually between 5 and 10 mg/L. The Cherry Branch site (intermediate) consistently had the highest DOC concentration and the Stony Brook site (high) had the lowest DOC concentrations.
Nitrate-N data for the four storm events sampled in the Spring of 2002 were quite low, less than 1 mg/L. The ammonium-N concentrations were less than 1 mg/L, except for the Oak Newell site, where the first sample was approximately 7 mg/L and decreased to between 1 and 2 mg/L thereafter. Soluble phosphate-P was at background levels for the Stoney Brook and Cherry Branch storm water sites for the entire event recorded. For the Smokerise site, the first bottle P concentration was 0.5 mg/L. As for the ammonium-N, the P values were highest for the Oak Newell storm water collection site. The first bottle P concentration was 1.6 mg/L. Phosphate concentrations decreased in subsequent bottles. The pattern for P and ammonium-N at the Oak Newell site leads one to speculate that the water contained plant nutrients from an application of ammonium phosphate, which is a very common turf fertilizer.
The leaf pack experiment and laboratory fungicide exposures investigating the impacts of lawn care practices on stream food webs and stream ecosystem processes are complete. Tulip-poplar leaf (Liriodendron tulipifera L.) breakdown rates were compared among streams and related to physical, chemical, and biological parameters. These correlations were related to variations in human lawn care practices in the watersheds. Nutrient and fungicide concentrations were low, with slight differences in nitrate-N among streams. There was significant fungal growth in four of the streams, but maximum ergosterol concentrations were low and similar among streams. There were significant differences in leaf breakdown rates among streams, ranging from 0.0006 in a suburban stream to 0.0024 degree day-1 in both reference streams. Breakdown rates were significantly and positively correlated with stream velocity, which differed significantly among streams. Velocity confounded the relationships between leaf breakdown rates and nutrient and fungicide concentrations. Physical factors appear to explain the variation in leaf breakdown rates among streams more than chemical or biological factors.
In the laboratory, we tested whether the concentrations of three fungicides, flutolanil, chlorothalonil, and its degradation product, 4-hydroxy-chlorothalonil (4OH-chlorothalonil) had an effect on the biomass and sporulation of aquatic fungi and decay rates of tulip-poplar leaves (L. tulipifera). Tulip-poplar leaves colonized by aquatic fungi and supplied with N and P were exposed to a range of fungicide concentrations in stream-simulating microcosms for 1 month. Low fungicide concentrations were comparable to those measured in suburban streams, and high concentrations were comparable to those measured at a golf course tile drain. With increasing 4OH-chlorothalonil concentrations, three measures of fungal growth decreased. No effect of chlorothalonil or flutolanil on fungal biomass and sporulation was observed. Significant leaf decay only occurred in the control flasks and in one of the flutolanil concentrations, but there was no leaf decay in the chlorothalonil or 4OH-chlorothalonil treatments. These low, but environmentally realistic concentrations of chlorothalonil, 4OH-chlorothalonil, and flutolanil inhibited leaf decay, but only the degradation product of chlorothalonil produced detectable reduction in fungal biomass.
The freshwater clam, Corbicula fluminea, was chosen as an indicator species because it is sedentary and abundant in many aquatic habitats throughout the southeastern United States. Specifically, biomarkers of oxidative stress were evaluated in assessments because a variety of different chemicals can cause damage by increasing levels of harmful oxygen radicals via processes of redox cycling, interfering with electron transport, inducing enzyme systems such as cytochrome P450s that mediate oxidation reactions, or by depleting levels of protective antioxidants. Clams exposed to low levels of contaminants exhibited transient signs of oxidative stress (i.e., elevated levels of superoxide dismutase, catalase and lipid peroxidation, and depleted glutathione concentrations), whereas condition indices were worse (lower) only at high exposures. These data suggest that clams may be able to compensate for adverse cellular effects, but the energy required for amelioration eventually will affect organismal health. From these data, we developed a discriminate model that describes how biomarker responses can be linked to higher levels of biological organization. Health scores computed by discriminate analysis represent biomarker response patterns in healthy clams (= 1), clams that display evidence of cellular stress but no adverse effects at the organismal level (= 2 or 3), and clams whose compensatory mechanisms are overwhelmed and that display adverse effects at the organismal level (= 4 or 5). Clams with poor health scores had significantly higher levels of contaminants in their tissues (P < 0.05). Clams with the worst health scores (= 5) were those from high-income sites in the residential study area during the wetter year and all golf course sites (US, TD, and DS). These data suggest that intense pesticide use on residential turf may be adversely impacting nearby streams during rain events. These data also suggest that the stream running through the golf course is degraded prior to entering the area, probably because of its location in an urban watershed. Although individual biomarker responses were worse downstream of the golf course than upstream, these data were not significant in the comprehensive discriminate model of clam health.
The effects of pulsed-exposures of chlorpyrifos, carbaryl and malathion, three insecticides commonly detected in urban watersheds, were assessed in the laboratory with black fly larvae Simulium vittatum IS-7. Larvae were exposed to the chemicals individually at concentrations approximately equal to 1 mg/L or as mixtures with concentrations of the individual chemicals summing 1 mg/L for 2 hours on days 1, 2, 3, 5, 7, and 9 of the 14-day flow-through experiment. Parameters measured were survival, growth rate, pupation rate, and overall pupation of the larvae. Results showed no significant difference in any of the parameters measured compared to controls indicating that aquatic organisms may be able to tolerate short exposures to insecticides at environmentally realistic concentrations.
Macroinvertebrate identifications for the Peachtree City sites and golf course sites are complete. Data currently are being incorporated into metrics and indices designed to assess overall stream health. Although data analysis is not complete, it appears that the Oak Newel (L), Stoneybrook (H2), Keg Creek (R2), and Crabapple (R1) sites are similar and in relatively good condition for the area. However, the Smokerise (H1) site appears to be moderately impacted, and the Cherry Branch (I) highly impacted. Linkages among the biological, physical, and chemical data have yet to be determined.
Objective 2. The premise of this research is that beliefs, values, and practices about lawn and lawn care are structured according to cultural models representing the knowledge needed to be a functioning member of one’s society or social group. The level of agreement or disagreement on beliefs, values, and practices about lawn and lawn care are expected to display clear social patterns of variation between homeowners, environmental custodians, horticultural writers, and lawn care professionals. Because “knowing better” does not always lead to “behaving correctly,” this research not only focuses on the beliefs and values about fertilizer application rates, mower blade height, species composition, but also the behavior that puts such principles into practice.
This research takes an integrated systems approach to determine the impact that turf care chemicals used on residential lawns have on nontarget aquatic ecosystems and the factors affecting the cultural beliefs and values guiding homeowner decisions about lawn care influencing chemical movement to aquatic ecosystems.
Expert Interviews. Twenty-five expert interviews (i.e., aesthetic guardians, environmental custodians, and lawn care professionals active in Peachtree City) were completed in the field. All interviews were transcribed, coded, and are in the process of being analyzed. In addition to the interviews, 21 proxy documents (i.e., reports, flyers, work policies, etc.) were obtained in the course of these interviews that provide context or additional insight on the content of the interview.
Geographic Information. Microwatershed boundaries were derived for the entire city based on a U.S. Geological Survey 30-m digital elevation model. This information was shared on demand with other researchers, and served as the basis for developing a list of potential homeowners to interview based on stratifying watersheds according to high- and low-value homes.
Homeowner Interviews. Twenty-four homeowner interviews were conducted during summer and early fall 2002, addressing: (1) knowledge, appearance, and information about lawn care; (2) decisionmaking and practice of lawn care; and (3) personal information on education, home modifications, and major landscaping. All interviews were transcribed and coded and currently are being analyzed.
Lawn Diaries. A subset of seven interviewed homeowners who agreed to record their lawn maintenance activities and expenses were recruited in the fall of 2002 to record their personal maintenance information. They began submitting their information on a weekly basis in January 2003.
Evolution of Landscape Design. Additional interviews were conducted on the historical development of landscape design of Peachtree City, along with the collection of historical documents and comparative assessments of similar cities. Two manuscripts are in preparation on architectural and landscape design particular to the research site.
Social Pressures of Residential Lawn Care. Four neighborhoods were selected according to neighborhood age and property value to focus on the motivations behind residential landscape maintenance. Eleven interviews were conducted on the beliefs and perceived social pressures associated with lawn care; a ranking exercise of images depicting residential landscapes in the study neighborhoods was used to elicit views on the quality of landscape maintenance. Interviews were transcribed, coded, and analyzed along with the numeric results from the ranking exercise. It will be used in a Masters of Science Thesis in Conservation and Sustainable Development entitled "Ecological Impacts of Social Process in Peachtree City, GA."
Future Activities:
The major focus for the last year of this project will be the completion of data analysis and the preparation of manuscripts for publication. In addition, chemical data from the Peachtree City sites will be used to help verify models, such as the RZWQM model, used to predict runoff and leaching from turfgrass areas. Socioeconomic surveys of the greater Atlanta area also will be conducted and the results will be analyzed.
Journal Articles on this Report : 7 Displayed | Download in RIS Format
Other project views: | All 71 publications | 17 publications in selected types | All 17 journal articles |
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Type | Citation | ||
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Conners DE, Black MC. Evaluation of lethality and genotoxicity in the freshwater mussel Utterbackia imbecillis (Bivalvia: Unionidae) exposed singly and in combination to chemicals used in lawn care. Archives of Environmental Contamination and Toxicology 2004;46(3):362-371. |
R828007 (2002) R828007 (Final) |
not available |
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Shuman LM. Fertilizer source effects on phosphate and nitrate leaching through simulated golf greens. Environmental Pollution 2003;125(3):413-421. |
R828007 (2002) R828007 (Final) |
not available |
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Shuman LM. Nutrient runoff in warm-season turfgrasses. Georgia Sod Producers Association News 2003;13(1):17-18. |
R828007 (2002) R828007 (Final) |
not available |
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Shuman LM. Runoff of nitrate nitrogen and phosphorus from turfgrass after "watering-in". Communications in Soil Science and Plant Analysis 2004;35(1-2):9-24. |
R828007 (2002) R828007 (Final) |
not available |
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Shuman LM. Nutrient leaching and runoff from golf courses. United States Golf Association Turfgrass and Environmental Research Online 2002;1(17):1-8. http:/turf.lib.msu.edu/tero/v01/n17.pdf |
R828007 (2002) R828007 (Final) |
not available |
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Shuman LM. Pesticide and nutrient fate: phosphorus leaching from golf greens. Through the Green, May/June, 2002, p. 38. |
R828007 (2001) R828007 (2002) R828007 (Final) |
not available |
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Shuman LM. Runoff: where is it coming from? From a warm-season perspective. Turf News 2002;26:43-49. |
R828007 (2002) R828007 (Final) |
not available |
Supplemental Keywords:
lawns, lawn care, suburbia, cultural models, policy, watersheds, ecological effects, dose-response, mixtures, pesticides, aquatic toxicology, macroinvertebrates, black flies., RFA, Scientific Discipline, Toxics, Geographic Area, Water, Ecosystem Protection/Environmental Exposure & Risk, Water & Watershed, Hydrology, Nutrients, Ecosystem/Assessment/Indicators, pesticides, State, Ecological Effects - Environmental Exposure & Risk, Southeast, Ecology and Ecosystems, Watersheds, fate and transport, nutrient transport, anthropogenic stress, aquatic ecosystem, nutrient supply, ecological effects, ecological exposure, contaminant transport, valuation of watersheds, suburban watersheds, stream ecosystems, bioavailability, river inputs, runoff, watershed sustainablity, Georgia (GA), Atlanta, Georgia, socioeconomics, chemical transport, ecological impacts, stormwater drainage, aquatic ecosystems, lawn care practices, pesticide runoff, bioindicators, homeowner beliefs, nutrient cycling, water quality, ecological indicators, herbecides, public policy, lawn care, community values, land useRelevant Websites:
http://anthro.dac.uga.edu/ Exit
http://coweeta.ecology.uga.edu Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.