Final Report: The Impact of Lawn Care Practices on Aquatic Ecosystems in Suburban Watersheds.

EPA Grant Number: R828007
Title: 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 , Alpharetta Environmental Services , Peachtree City Developmental Services , Mississippi State University - Main Campus
Current Institution: University of Georgia , Alpharetta Environmental Services , Mississippi State University - Main Campus , Peachtree City Developmental Services
EPA Project Officer: Packard, Benjamin H
Project Period: March 1, 2000 through February 28, 2003
Project Amount: $893,849
RFA: Water and Watersheds (1999) RFA Text |  Recipients Lists
Research Category: Water and Watersheds , Water

Objective:

The working hypothesis of this project was that 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 project were 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.

Summary/Accomplishments (Outputs/Outcomes):

Objective 1

Pesticide Monitoring and Analysis. Monthly samples of water and sediment were collected from streams, and water from tile drains was collected based upon either rainstorm or “green flushing” events. Water collected from fairway runoff was based upon rainstorm events. Samples from water and sediment were analyzed for commonly used turf pesticides, whereas pesticides monitored in tile drainage and fairway runoff were based upon 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 were frequently detected as were chlorothalonil (CHT) and its main degradation product, 4-hydroxy-2,5,6-trichloroisophthalonitrile (hydroxychlorothalonil; OH-CHT). Prodiamine, pendimethalin, and diazinon also were detected but at lower frequency. Generally pesticidal loadings from neighborhoods were not associated with level of income as with 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 in the spring and fall, respectively. The fungicides CHT and flutolanil were the most heavily applied chemicals to the greens. OH-CHT was commonly detected at low part-per-million concentrations but was detected at high part-per-trillion concentrations in a stream directly receiving this drainage, indicating the occurrence of significant dilution of tile drainage. 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 chemical

The Fate of Chlorothalonil in Irradiated Water-Sediment Systems. Many pollutants in aquatic systems will associate with sediment, and their fate in such systems is important to assess potential biological impacts. Water/sediment systems incorporating simulated sunlight were designed to simulate shallow water conditions. Experiments were run in the light and dark simultaneously for 30 days in both creek and pond sediment systems. The extraction recoveries for CHT and OH-CHT were 90 percent and 84 percent from creek sediment and 86 percent and 78 percent from pond sediment, respectively. Of the total applied CHT, 87-88 percent had dissipated from both water/sediment systems within 1 day when irradiated by simulated sunlight light. In contrast, 60-68 percent of the applied chemical remained in the water at day 1 in the dark. Approximately 3-6 percent and 10-16 percent of the applied CHT were found in sediments under light conditions at day 1 and in the dark at day 3, respectively, which are the highest amounts observed during the experimental period. These levels subsequently declined, indicating that sediment probably is not a major sink for CHT in aquatic systems. OH-CHT, a major degradation product/metabolite, was detected only in the dark systems and ranged in concentration from 0.003 to 0.016 μg/ml. The total recoveries (water + sediment) under light conditions at day 1 were just 15-17 percent versus 68-79 percent in the dark, suggesting that photodegradation is important to the dissipation of CHT in aqueous environments.

Nutrients at Peachtree City Sites. At the six Peachtree City sites, nitrate-N water concentrations were typically below 0.5 mg/L. Oak Newel tended to have the highest concentrations and Cherry Branch the lowest. During the dry years of 2001 and 2002, the nitrate-N concentrations tended to increase from January to August and decrease in the fall. The pattern for 2003, a wet year, was different. The ammonium-N concentrations were very low with most being below 0.1 mg/L. Typically, Cherry Branch had the highest concentrations and Stoney Brook the lowest. Soluble reactive P concentrations were typically below 15 µg/L. P concentrations were higher during times of high rainfall and high turbidity. At Cherry Branch, P concentrations exceeded 40 µg/L in July 2003, after heavy rainfall all summer. Turbidity and total suspended solids were well correlated (0.97 correlation coefficient for all dates and sites). Turbidity increased in response to higher rainfall. The dissolved organic carbon (DOC) values were generally stable the entire time. Cherry Branch usually had the highest DOC concentrations and Stoney Brook the lowest.

One interesting feature of the nitrogen and phosphorus data is that the ammonium-N concentrations and the soluble P concentrations were correlated at the 5 percent level only for the Smoke Rise and Stoney Brook sites, which were the high-income sites. No other sites had this significant correlation. The reason this may have some importance is that diammonium phosphate is one of the most common fertilizers, and the correlations may indicate that the water was affected by lawn fertilizers. Other correlations that were significant for a majority of the sites were ammonium-N versus nitrate-N, turbidity versus total suspended solids, and both forms of nitrogen versus solids (total suspended solids and turbidity).

During stormwater sampling, nitrate-N concentrations for the event sampled were low for the Smoke Rise and Stoney Brook sites, but approximately 0.5 mg/L for Cherry Branch and as high as 1 mg/L for Oak Newel. These latter two sites had nitrate-N concentrations higher than base-flow values. Ammonium-N concentrations for Stoney Brook and Cherry Branch were low and similar to the base-flow values. Smoke Rise, however, had an ammonium-N concentration as high as 2 mg/L and Oak Newell as high as 7 mg/L, which is greater than the base-flow concentrations (0.1 mg/L). The soluble P was likewise high at Smoke Rise (500 µg/L) and Oak Newel (1500 µg/L). It would seem that the storm water at the Smoke Rise and Oak Newel sites were affected by ammonium phosphate lawn fertilizers.

Nutrients at the Golf Course. At Camp Creek, flowing through the Golf Club of Georgia, nitrate-N concentrations were generally less than 0.5 mg/L but were slightly higher than for the Peachtree City sites in the winter and spring of 2002 and 2003. At sites upstream and downstream of the course, nitrate-N concentrations were similar. Ammonium-N concentrations were very low (< 0.2 mg/L) and similar to the Peachtree City sites. Upstream and downstream ammonium-N concentrations were the same. Soluble P concentrations were very low, except for September 2002 and July 2003. For both these peaks, the downstream concentrations were higher than the upstream concentrations. High P concentrations seem to correspond with high turbidity values in July of 2003. The turbidity values showed several peaks at June 2001 (where downstream was higher), January 2002 (where up and downstream were the same), and an increase from May through July 2003. DOC concentrations were generally less than 10 mg/L similar to the Peachtree City sites, and there were no differences between upstream and downstream values.

Metals in Sediments at Peachtree City Sites. All the Zn concentrations were near the 20 mg/kg level. Zn values for Smoke Rise were usually the highest and Keg Creek and Crabapple (reference sites) the lowest. The Cu values were all below 2 mg/L with the exception of Smoke Rise, which had Cu values between 6 and 12 mg/L. The As values were generally below 300 µg/kg. Smoke Rise had the highest As values at around 400 µg/kg with some peaks as high as 800 to 1,000 µg/kg.

Metals in Water at Peachtree City Sites. All water concentrations for Cu and As were below the detection limits except for Smoke Rise for May 2001. For Zn, the concentrations mostly were between 5 to 7 µg/L.

Toxicity of Insecticide Mixtures. Multiple insecticides are routinely detected in urban waterways. Thus, it is necessary to understand the toxic nature of insecticide mixtures to determine potential impacts on aquatic invertebrates. Three of the most common lawn care insecticides detected in urban watersheds, carbaryl, chlorpyrifos, and malathion, were evaluated using an acute orbital shaker toxicity test to determine their respective median lethal concentrations (LC50s) to Simulium vittatum Zetterstedt cytospecies IS-7 larvae. Results of the 48-hour LC50 tests show chlorpyrifos to be the most toxic to black fly larvae (LC50 = 0.28 mg/L) followed by carbaryl (LC50 = 23.72 mg/L), and malathion (LC50 = 54.20 mg/L). These insecticides also were tested as binary and ternary mixtures using the toxic unit (TU) approach. Toxicity was shown to be greater than additive for the ternary mixture of chlorpyrifos-carbaryl-malathion (LC50 = 0.56 TU), and the binary mixtures of chlorpyrifos-malathion (LC50 = 0.72 TU), and carbaryl-malathion (LC50 = 0.78 TU). The binary combination of chlorpyrifos and carbaryl was shown to be additive (LC50 = 0.98 TU). These results indicate that aquatic invertebrate populations in urban and suburban streams may experience a higher-than-expected increase in toxicity-related effects when all three chemicals are present in the waterway.

Because pesticides often enter waterways in a pulsed fashion during storm events, it was of interest to study the effects of short-term exposures of high concentrations of pesticides to aquatic invertebrates. The effects of the insecticides chlorpyrifos, malathion, and carbaryl, individually and as mixtures, on growth, development, and survival of black fly larvae, S. vittatum IS-7, were investigated using a trough flow-through dosing system. Black fly larvae were exposed to multiple 2 hour pulses of the individual insecticides at concentrations approximately equal to 1 mg/L (an environmentally realistic concentration) and mixtures with the summation of individual components approximately equivalent to 1 mg/L followed by periods of clean water between exposures over the 14 day experiments. Results showed that 2 hour pulse exposures of the insecticides individually or as mixtures had no significant effect on growth, development, or survival of S. vittatum IS-7 larvae. Because of the high variance associated with these parameters, however, additional replications need to be conducted to increase the power of the statistical analyses, which will aid in determining if effects are actually taking place.

Macroinvertebrate Assessment of Peachtree City Sites. The macroinvertebrate communities of six streams in Peachtree City, Georgia, were assessed quarterly between June 2000 and April 2002 using the U.S. Environmental Protection Agency’s (EPA) Rapid Bioassessment Protocol for Wadeable Streams and Rivers with multimetric data analysis to determine the impacts of lawn care chemical runoff. Streams also were ranked using a pesticide toxicity index to determine if impairment detected with the macroinvertebrate data was related to pesticide exposure. Results of the metric analysis showed that the Oak Newel site had the highest ecological integrity, scoring highest in 4 out of the 10 benthic metrics used in the assessment. The Keg Creek, Stoney Brook, and Crabapple sites were statistically similar in greater than or equal to 90 percent of the metrics and statistically similar to Oak Newel in greater than or equal to 80 percent of the metrics. The Smoke Rise and Cherry Branch sites were statistically similar with each other in 90 percent of the metrics. They were similar to Oak Newel, however, in less than 40 percent of the metrics indicating impairment.

A series of correlation analyses were conducted comparing stream rank from physical stream parameters, habitat assessments, water quality, macroinvertebrate metric, pesticide toxicity, and metal toxicity data to determine relationships among these parameters. A significant correlation was detected between stream ranks for pesticide toxicity and macroinvertebrate metrics (p < 0.05). Increased ecological integrity as determined by the macroinvertebrate metric data was significantly correlated with a decrease in specific conductance (τ = 0.94, n = 6, p < 0.05), an increase in turbidity (τ = 0.94, n = 6, p < 0.05), a decrease in temperature (τ = 1.69, n = 6, p < 0.05), and an increase in dissolved oxygen (τ = 1.69, n = 6, p < 0.05). No physical parameters or habitat quality were significantly correlated with the macroinvertebrate metrics (p > 0.05). Because there was a significant correlation between the pesticide toxicity index and the macroinvertebrate metrics, additional correlation analyses were conducted to determine which metrics best predicted pesticide effects. The North Carolina Biotic Index (NCBI) and the Biotic Condition Index (BCI) had the highest correlation with the pesticide toxicity index data (p < 0.01). The percent Ephemeroptera, Plecoptera, Trichoptera (EPT) taxa, percent Chironomidae, and percent Clinger taxa metrics also were significantly correlated with the pesticide toxicity index data (p < 0.05). There was no correlation between the property value of homes within the respective watersheds and integrity of the macroinvertebrate community. These results indicate that lawn care pesticides and select water quality parameters have a more profound effect on the macroinvertebrates inhabiting these streams than physical parameters, habitat, and other contaminants, such as metals, in this study.

Macroinvertebrate Assessments at the Golf Course. Camp Creek was assessed at two locations at the Golf Club of Georgia, upstream of the 11th hole tee box (upstream reference) and adjacent to the 13th fairway and green (downstream study site) to determine the impacts of lawn care chemicals applied to the golf course turf on the macroinvertebrate community. Macroinvertebrates were collected quarterly between October 2000 and July 2002 using EPA’s Rapid Bioassessment Protocols for use in Wadeable Streams and Rivers. The macroinvertebrate data was analyzed using a multimetric approach. Of the nine metrics used to assess the macroinvertebrate community, four were statistically different among the upstream and downstream sites. The upstream site had statistically higher ecological integrity based on the percent EPT abundance, EPT richness, percent Clinger taxa, and NCBI metrics (p < 0.05). The habitat quality of the downstream site, however, was poor for macroinvertebrates compared to the upstream site. Water velocity was restricted as a result of beaver dam construction and the creek bottom was highly sedimented, which made this portion of Camp Creek more a lentic than lotic environment. Thus, the lack of many macroinvertebrate taxa is likely related to physical constraints of the habitat rather than chemical impacts, considering concentrations of pesticides were higher at the upstream site compared to the downstream site. In addition, comparison of the metric data for Camp Creek with data from other reference streams in the area indicate that the creek is impaired before it enters the golf course.

Effects of Lawn Care Fungicides on Aquatic Fungi and Leaf Decay. Stream foodwebs could be altered by adverse effects of pesticides on nontarget organisms, such as aquatic fungi, that play a crucial role in leaf breakdown in streams. In this study, we tested whether the concentrations of three fungicides typically found in suburban streams had an effect on the biomass and sporulation rates of aquatic fungi and decay rates of tulip popular (Liriodendron tulipifera) leaves. The fungicides flutolanil, CHT, and its degradation product OH-CHT, were investigated using low fungicide concentrations that were comparable to those measured in suburban streams and high concentrations that were comparable to those measured at a golf course. Tulip poplar leaves colonized by aquatic fungi were exposed to a range of fungicide concentrations in stream-simulating microcosms containing nutrients. With increases in OH-CHT concentrations, measures of fungal growth decreased. No effect of CHT or flutolanil on fungal biomass and sporulation rates was observed. Significant leaf decay occurred only in the control flasks and one of the flutolanil treatments. These low but environmentally realistic fungicide concentrations inhibited leaf decay but only the degradation product, OH-CHT, produced a detectable reduction in fungal biomass. This degradation product was detected in 99 percent of Peachtree City stream samples (data in other sections of this report). Increased detection frequencies of fungicides and especially their degradation products in streams demonstrate the need for further research on the adverse effects of these compounds on nontarget organisms and ecological processes.

Algal Biomass and Species in Suburban Streams. Standing stock of chlorophyll was measured seasonally for 2 years in all streams. Chlorophyll ranged from less than 5 to 25 mg/m2. Seasonal patterns of chlorophyll differed among streams, but those differences were not consistent within neighborhood type. Highest benthic algal biomass was observed in spring 2001, but there were no significant differences among streams. Number of diatom cells ranged from 29,260 to 347,164 cells/cm2, and there were no consistent differences among streams in different neighborhood types. The highest number of diatom species (63-64) was found in Smoke Rise and Stoney Brook, with somewhat fewer (42-57) in the other stream types. Several taxa were common in nearly all streams (e.g., Achnanthidium and Gomphonema), but there are few consistent differences among streams in different neighborhood types. Although there are obviously differences among algae in these streams, the differences do not seem to be related to the type of neighborhood through which the stream flows.

Impact of Lawn Care Practices on Leaf Breakdown and Fungal Biomass in Suburban Streams. Pesticides and nutrients frequently are detected in suburban streams, where stormwater runoff from residential lawns is routed directly to streams. Adverse effects of these lawn care products on basal food resources and ecosystem processes in streams, however, are not well understood. The impact of lawn care practices on the breakdown of tulip poplar leaves (Liriodendron tulipifera) and fungal biomass (measured as ergosterol) was investigated in streams flowing through four suburban watersheds and two mixed-use watersheds in Peachtree City, Georgia. Tulip poplar leaves were collected as they fell from trees during autumn 2000. Fifty air-dried, 8 g leaf packs in coarse-mesh bags were assembled and placed in the six streams in Peachtree City, Georgia, in November 2000. Packs were removed at intervals, and weight loss was determined. We also measured other variables that can influence leaf breakdown rates: temperature, water velocity, accumulation of sediment, fungal biomass, and invertebrate abundance in leaf packs. We relate measured leaf breakdown rate to stream water nutrient and pesticide concentrations that were measured in other parts of this project.

Breakdown rates are reported per degree day to eliminate the confounding effects of temperature differences among streams. Leaf breakdown rates measured in the high property value streams, Smoke Rise and Stoney Brook, are lower than reported in other studies in more forested watersheds, whereas rates measured in the other streams in this study are similar to those measured in forested watersheds. Although water velocity, dissolved inorganic N concentrations, amount of sediment accumulating in packs, and shredder biomass differed among streams during the experimental period, the only environmental variable significantly related to leaf breakdown rate is water velocity (k/dd = 0.0002 velocity [cm/s] + 0.0001, r2 = 0.65, p = 0.05). Measured concentrations of fungicides (CHT and its degradation product OH-CHT) and pesticide toxicity indices calculated by others on this project did not relate to leaf breakdown rate.

When leaf breakdown data are combined within streams flowing through watersheds with similar property value, breakdown rate is highest (0.0024 ± 0.0004 dd-1) in the reference streams (Crabapple and Keg Creek), intermediate (0.0015 ± 0.0002 dd-1) in the low and intermediate home value streams (Cherry Branch and Oak Newel), and slowest in the high home value (0.0008 ± 0.0003 dd-1) streams (Smoke Rise and Stoney Brook) (p < 0.05). Similar differences were observed when loss of leaf standing crop in the streams was measured from December through March. Losses of leaf standing crop were only 47-59 percent in high property value streams and 78-90 percent in the others. These differences in breakdown rate and mass loss can be understood in the context of differences in velocity among streams. The reference streams have highest velocity because they drain the largest watersheds. The velocities are higher in the watersheds with property of lower and intermediate value than in watersheds with higher property value because impervious surface cover is higher (10.1% and 15.4%) in the former than in the latter (7.1% and 2.4%). This suggests that stormwater runoff likely differs among these watersheds. Despite the fact that this experiment was conducted in a period of relatively low rainfall, physical factors associated with higher water velocity appear to override chemical or biological factors in controlling leaf breakdown rates in these streams.

In Situ Bivalve Assessment-Biomarker Analysis. The purpose of this research was to develop sensitive biomarkers of stress in freshwater clams (Corbicula fluminea) for use as mechanistic tools to evaluate the degradation of streams by turf contaminants. Many xenobiotics cause damage in aquatic organisms via oxidative stress mechanisms, therefore, measurements of stress used in this study included antioxidants (superoxide dismutase, catalase, and glutathione), indicators of cellular oxidative damage (lipid peroxidation), an indicator of exposure to organophosphate and carbamate pesticides (acetylcholinesterase inhibition), an indicator of DNA damage (Comet assay), and an indicator of organismal health (condition index). Of 16 chemicals evaluated, only 7 were detected frequently (> 20 %) and at levels above the limit of quantification in deployed clams tissues. These contaminants of concern (COC) were the herbicides trifluralin (83%) and pendimethalin (79%), the insecticide chlorpyrifos (83%), the fungicide degradation product OH-CHT (66.7%), and the metals As (100%), Cu (100%), and Zn (100%). Although the presence of COCs in clam tissues is suggestive of their use by homeowners and professional applicators in the watersheds, detection frequencies also were related to the lipophilicity of chemicals (log Kow > 5.0 for all organic pesticides except OH-CHT). Within the residential streams, contaminants were typically higher in clams deployed at the high property value sites, Smoke Rise and Stoney Brook, and at Keg Creek, a large stream where after this study was performed, it was discovered that pesticides were being used in the watershed for management of surrounding pine plantations. Within the golf course study area, contaminants were typically highest in clams from the downstream site. Contaminants tended to be higher in clams during 2001, a year with more rainfall and more runoff to streams (average stream velocities during clam deployments in 2000 were 3.2 ± 1.5 cm/s and in 2001 were 13.4 ± 3.7 cm/s). No inhibition of acetylcholinesterase, a biomarker indicating exposure to organophosphate and carbamate pesticides, was detected in clams from any site during either year in clams, although high variability of the data may have masked any differences among sites.

Clams exposed in situ to turf contaminants exhibited transient signs of oxidative stress (i.e., elevated levels of superoxide dismutase, catalase, glutathione, and lipid peroxidation), whereas condition indices were worse only at high exposures. These data suggest that clams may be able to compensate for adverse cellular effects, but energy required for amelioration will eventually affect organismal health. Such responses have been observed in other aquatic organisms exposed to contaminants.

A discriminate analysis of bioeffects data identified five groups that were given health scores to reflect bioeffect 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 responses are overwhelmed and display adverse effects at the organismal level (= 4 or 5). Once discriminated, the model correctly reclassified 60 percent of the data. Clams with the worst health scores (= 5) were those from high property value sites, Smoke Rise and Stoney Brook, and large streams, Keg Creek, in the residential study area during the wet year and all golf course sites (upstream, TD, and downstream). Clams with the worst health scores had significantly elevated levels of turf contaminants in their tissues. These data suggest that intense pesticide use on residential turf may be adversely impacting nearby streams during rain events, and that the stream running through the golf course is likely degraded prior to entering the area because of its location in a highly urbanized watershed.

A laboratory study was conducted to confirm that the observed effects on clam health were caused by the turf contaminants accumulated by clams and not by other contaminants that may co-occur in the streams but were not measured. Realistic concentrations of a complex turf COC mixture induced oxidative stress in laboratory-exposed clams but not to the extent as observed in the field where exposures may have been more severe because of the presence of other contaminants. Together, these data suggest that turf contaminants may be important contributors to the etiology of stress in freshwater clams from urbanized streams. In conclusion, this research highlights the sensitivity and utility of the use of suites of oxidative stress biomarkers for detecting adverse effects during environmentally relevant exposure scenarios and illustrates how such data may be simplified to a health score that would facilitate the communication of risks to environmental managers and the general public.

Objective 2

Our research in Peachtree City addressed the nature and dynamics of the residential land aesthetic. People’s preference for residential lawns is well documented. Even the environmentally aware often possess an unwavering preference for conventional residential lawns despite the challenges such maintenance practices can exert on the ecological integrity of their surroundings.

Research demonstrates that people prefer, and find more beautiful, landscapes that are open with even ground cover and occasional groupings of trees that give an overall impression of moderate to high landscape complexity yet retain legibility and an element of mystery. Such landscapes are said to be “park-like.” Among other reasons, people prefer such landscapes in residential areas because they communicate information vital to building their social reputation.

This research took a pragmatic perspective on such claims and used a mixed methods approach to explore and explain the problem. Spatially explicit social and development data were obtained in 2001 from the Peachtree City Engineering Office and imported to ArcGIS 8.1. Databases of potential homeowners for interviewing were developed from this data based on their geographic distribution. The homeowner interview protocol was developed to address beliefs, values, and lawn care practices. Four neighborhoods were selected based on three selection criteria: neighborhood age, property value, and the presence of a homeowners’ association. The last criterion was included because of its potential impact on the regulation of landscape maintenance and social process within its associated neighborhood.

Participants identified pride of ownership, respect for neighbors, and pride of place as the primary motivations for maintaining their residential landscapes. They emphasized the importance of context for evaluating quality of maintenance. They also noted the importance of a lawn’s consistency with its surroundings, as well as the overall flow and balance of landscape throughout a neighborhood. Participants furthermore described how neighborhood social process affected their decisions about residential landscape maintenance. Results of the tabular analysis indicate that participants within neighborhood were highly consistent in their overall ranking of landscapes, but differences between neighborhoods were significant.

The NL neighborhood is located on a cul-de-sac on a single straight street with small lots, little change in topography, and young trees (because of the age of the neighborhood). The OH neighborhood is located on a meandering loop street with large lots, mature trees, and extreme topography that makes the maintenance of turf grass very difficult for a great many residents. Residents of higher property value neighborhoods seem to be less receptive to deviations from their community standard than residents of other neighborhoods.

In conclusion, there is room for design cues to evolve into new ones that are perhaps more closely associated with the information communicated. Planned development at the community scale can facilitate this process. The design can then be sensitive to neighborhood dynamics and emphasize the importance of ecological conservation through regulation at the community level. Through such means, designers can facilitate not only the evolution of a new landscape aesthetic but also the development of a higher quality of suburban life.

Economics of Peachtree City Lawn Care. The economic work focused on homeowner decisions that affect both lawn quality and environmental quality. We paid particular attention to decisions about chemical use, fertilizers, irrigation choices, and the use of professional lawn care services. We also produced statistical information on the amount of time and money spent overall on lawn care and maintenance.

The activities most likely to be associated with environmental damage are the purchase and application of herbicides, pesticides, and synthetic fertilizers. The average Peachtree City household spent 20 hours per year on these tasks and reported spending $103. Among the 48 percent of households that applied non-zero amounts of these products, the average amount of time spent was 36 hours and the average expenditure was $215. Of the 23 percent of Peachtree City households that used biological pest controls and low-toxicity insecticides, an average of 6 hours and $44 were spent on these products. This is significantly more time and money than is used on biological pest controls (2 hours and $51).

Water use is also a critical variable for the environmental impact of lawn care, not because of direct impact on stream quality but because increasing surface water flows is generally important to ecosystem health during the summer months in Georgia. Thirty-five percent of Peachtree City households have automatic underground sprinkler systems, and nine percent have automatic drip systems. Thirty-six percent of households used a hose or watering can on their lawns. Fifty-one percent of Peachtree City households spent time watering their lawns, averaging 61 hours per year.

Peachtree City households were aware of the importance of watering their lawn during cooler parts of the day. Only 4 percent reported watering between 10 a.m. and 4 p.m., with 54 percent watering in the morning before 10 a.m. and 42 percent watering after 4 p.m. Residents reported that their watering decisions were influenced most strongly by knowledge of drought and watering restrictions, followed closely by concern about the appearance of their lawns. Half of the respondents watered less and changed their watering to cooler parts of the day because of their awareness of Georgia’s drought conditions. Twenty-two percent reported that they increased the amount they watered because drought conditions increased their lawn’s need for water. Twenty-one percent reported making changes in the composition of their yard so that less irrigation would be required.

Peachtree City residents generally prefer working to improve and maintain their plants and gardens to working on their lawns. Seventy-three percent reported that caring for their gardens was more a pleasant hobby than an unpleasant chore, whereas only 45 percent reported that caring for their lawns was more a pleasant hobby than an unpleasant chore. The need to maintain neighborhood standards was a more important determinant of lawn care labor choices than of choices about working with plants and gardens.

Fifty-six percent of Peachtree City respondents reported paying someone to work on their lawns within the past year. Thirty percent used a chemical applicator (i.e., Chemlawn), paying an average of $647. Fifty-seven percent hired a landscape maintenance company at an annual average of $1,064. Eleven percent hired a gardener or handyman (average payment of $795) whereas the seventeen percent that hired a neighborhood teenager paid an average of $414.

Among providers of professional lawn care services, the chemical applicator companies were by far the most likely to perform tasks involving the application of pesticides, herbicides, and fertilizer applications. Eighty-one percent of those hiring these companies had them apply herbicides and fertilizers, and 57 percent reported that they applied insecticides. Among landscape maintenance companies, 60 percent applied fertilizer, 42 percent applied herbicides, and 32 percent applied insecticides. Among other paid service providers (gardeners and neighborhood teenagers), only 7 percent applied fertilizers and insecticides and none applied herbicides.

Income has a positive relationship with money spent on pesticides, herbicides, and fertilizers, but there is no particular relationship between income and hours spent by homeowners on these tasks. Education does not significantly affect either expenditures on these products or hours spent. Neither income nor education has any explanatory power over whether Peachtree City residents choose to hire chemical applicators or landscape maintenance companies for lawn care work.

Income does not strongly explain individual components of lawn care expenditures, but it has a highly statistically significant relationship with total expenditures on lawn and garden maintenance. For Peachtree City residents, each additional hundred dollars of income is associated with about $1 of additional expenditures on lawns and gardens. The average total expenditure for Peachtree City residents is $921 per year, a significant share of family income.

The overall picture that emerges is that Peachtree City residents have a diverse set of labor and expenditure patterns toward their lawns. Activities with the potential for environmental damage are widely but not universally practiced. Professional applicators and maintenance companies are prevalent, but household labor also is a very significant part of the pattern in applying insecticides, herbicides, and fertilizers. Yards and lawns are important to the surveyed homeowners, who spend a significant amount of money on their outdoor environments. The use of potentially damaging products is a central part of the care and maintenance of this investment.


Journal Articles on this Report : 16 Displayed | Download in RIS Format

Other project views: All 71 publications 17 publications in selected types All 17 journal articles
Type Citation Project Document Sources
Journal Article Armbrust KL. Photodegradation of hydroxychlorothalonil in aqueous solution. Environmental Toxicology and Chemistry 2001;20(12):2699-2703. R828007 (Final)
not available
Journal Article Armbrust KL. Influence of soil binding potential on pesticide runoff. GTA Today, July/August, 2001. R828007 (2001)
R828007 (Final)
not available
Journal Article Armbrust KL. Pesticide runoff from turf. Through the Green, July/August, 2001. R828007 (2001)
R828007 (Final)
not available
Journal Article 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
Journal Article Overmyer JP, Armbrust KL, Noblet R. Susceptibility of black fly larvae (Diptera : Simuliidae) to lawn-care insecticides individually and as mixtures. Environmental Toxicology and Chemistry 2003;22(7):1582-1588 R828007 (Final)
not available
Journal Article Shuman LM. Phosphate and nitrate movement through simulated golf greens. Water, Air, and Soil Pollution 2001;129(1-4):305-318. R828007 (2001)
R828007 (Final)
not available
Journal Article Shuman LM. Runoff of phosphorus from simulated golf fairways. Turfgrass Trends 2001;10:1-4. R828007 (2001)
R828007 (Final)
not available
Journal Article Shuman LM. Phosphorus and nitrate nitrogen in runoff following fertilizer application to turfgrass. Journal of Environmental Quality 2002;31(5):1710-1715. R828007 (Final)
not available
Journal Article 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
Journal Article Shuman LM. Nutrient runoff in warm-season turfgrasses. Georgia Sod Producers Association News 2003;13(1):17-18. R828007 (2002)
R828007 (Final)
not available
Journal Article 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
Journal Article Shuman LM. Nitrogen and phosphorus loss from greens and fairways. USGA Green Section Record 2001;39:17-18. R828007 (2001)
R828007 (Final)
not available
Journal Article 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
Journal Article 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
Journal Article Shuman LM. Phosphorus movement from turfgrass. Georgia Turfgrass Association Today 2003;18:3-4. R828007 (Final)
not available
Journal Article 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, Hydrology, Nutrients, Water & Watershed, 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 use

Relevant Websites:

http://anthro.dac.uga.edu/ Exit
http://coweeta.ecology.uga.edu Exit

Progress and Final Reports:

Original Abstract
  • 2000 Progress Report
  • 2001 Progress Report