Land Application Site Research Articles

Evaluation of Fecal Indicators and Pathogens in a Beef Cattle Feedlot Vegetative Treatment System.

Runoff from open-lot animal feeding areas contains microorganisms that may adversely affect human and animal health if not properly managed. One alternative to full manure containment systems is a vegetative treatment system (VTS) that collects runoff in a sediment basin and then applies it to a perennial vegetation (grass) treatment area that is harvested for hay. Little is known regarding the efficacy of large-scale commercial VTSs for the removal of microbial contaminants. In this study, an active, pump-based VTS designed and built for a 1200-head beef cattle feedlot operation was examined to determine the effects of repeated feedlot runoff application on fecal indicator microorganisms and pathogens over short-term (2 wk) and long-term (3 yr) operations and whether fecal bacteria were infiltrating into deeper soils within the treatment area. In a short-term study, fecal bacteria and pathogen numbers declined over time in soil. Measurements of total coliforms and Enterococcus counts taken on control soils were not effective as fecal indicators. The repeated application of manure-impacted runoff as irrigation water did not enrich the pathogens or fecal indicators in the soil, and no evidence was seen to indicate that pathogens were moving into the deeper soil at this site. These results indicate that large-scale, active VTSs reduce the potential for environmental contamination by manure-associated bacteria. Also, this study has implications to full-containment systems that apply runoff water to land application areas (cropland) and the fate of pathogens in the soils of land application sites.

A glance behind and a look ahead: history and future of a regional biosolids authority

Regional utility, water or wastewater partnerships have existed for many years with varying degrees of success. In the early 2000's, leaders from two west Michigan communities came together with the idea of forming a regional biosolids program. Drivers for this effort primarily included increasing costs of existing programs, loss of land application sites, and age/condition of existing facilities. A project team was formed, a consultant was hired, and by 2004 the Cities of Grand Rapids and Wyoming formally signed the Articles of Incorporation forming the Grand Valley Regional Biosolids Authority (GVRBA). In 2009, a regional dewatering facility became operational. The economic downturn of 2007–2011 resulted in significant deviance from projected volume and costs, yet each community remains committed to the GVRBA and has recently begun incorporating the concept of sustainability into the program. The history, key drivers, benefits, disadvantages, and future of the GVRBA are further explored in this paper.

Application of a Dynamic Model to Assess Microbial Health Risks Associated with Beneficial Uses of Biosolids

Microbial risk assessment is a structured approach to estimating risks associated with environmental exposure to pathogens by using available environmental data. In this report the researchers took advantage of three sources of environmental data to estimate risk: 1) pathogen monitoring of raw sludge efficacy of treatment processes, and pathogen monitoring of post-treatment biosolids. This risk assessment approach is able to estimate risks even for Class A biosolids where post-treatment monitoring data are all below the detectable level. Using this approach the researchers provide risk estimates for a number of different models to gain insight into risks associated with different aspects of the biosolids treatment and application process. This report provides an approach to conducting risk assessments that takes advantage of pathogen data from raw sludge and data on treatment process efficacy as additional data sources to the post-treatment data. In this context the raw sludge and treatment data are considered prior information that can inform the risk estimate, and the post treatment data is used to inform the likelihood. A Bayesian structure like this one can be used to take full advantage of the available data into order to obtain the best risk estimate. As with any Bayesian analysis, if the data informing the likelihood is sparse, the posterior (or risk estimate) is strongly influenced by the prior. As the data improves, the posterior (or risk estimate) is influenced less by the prior. The reserachers provide risk estimates to illustrate how this can be used both in a regulatory context to make risk-based rules, and in a operation context to examine the benefits of changing treatment processes in the context of current application practices or proposed new practices. Biosolids producers can use the results of this research to interpret the results and potential health implications of biosolids monitoring data. Treatment plant engineers can evaluate the potential risk-based benefits of making operational changes to existing treatment and/or adding additional treatment processes, and environmental managers can use this research to evaluate potential capitol improvements and/or land application site placement issues from a health-based perspective. Regulators at the U.S. EPA can use this framework to develop risk-based regulations parallel to the chemical contaminant rules. The risk assessment framework present in this report provides a mechanism to discuss biosolids management microbial risk using a common metric for comparison of treatment methods, management alternatives, and potentially to set risk-based standards for microbial contaminants in biosolids. This title belongs to WERF Research Report Series ISBN: 9781843397625 (Print) ISBN: 9781780403892 (eBook)

Epidemiologic Surveillance and Investigation of Symptoms of Illness by Neighbors of Biosolids Land Application Sites

Wastewaters from homes, businesses and public facilities require treatment to protect human and environmental health. In the process of cleaning water for release to the environment, treatment plants separate solids (sludge), which contain nutrients useful in agriculture as well as microbes and chemicals from the wastewater stream. Treated sludges are referred to as biosolids. A majority of biosolids produced in the United States are applied to agricultural land as a fertilizer or soil amendment. While this practice is regulated by the United States Environmental Protection Agency, the public has expressed concerns about its potential effects on human health, and the National Academy of Sciences has recommended establishing a framework for human health investigations.The primary goal of this project is to develop an investigation protocol to assist environmental and public health officials in responding to citizens and medical providers who report symptoms that they attribute to land application of biosolids. Data resulting from citizen and provider reports and subsequent investigations will be compiled into a database that will be used to advance research into the safety of current biosolids land application practices.This title belongs to WERF Research Report SeriesISBN: 9781843397922 (eBook)

Denitrification Field Study at a Wastewater Land Application Site

AbstractA few risks restrict the sustainable development of wastewater land application including potential nitrogen contamination to groundwater. One important component is nitrogen loss caused by...

Source tracking swine fecal waste in surface water proximal to swine concentrated animal feeding operations

Swine farming has gone through many changes in the last few decades, resulting in operations with a high animal density known as confined animal feeding operations (CAFOs). These operations produce a large quantity of fecal waste whose environmental impacts are not well understood. The purpose of this study was to investigate microbial water quality in surface waters proximal to swine CAFOs including microbial source tracking of fecal microbes specific to swine. For one year, surface water samples at up- and downstream sites proximal to swine CAFO lagoon waste land application sites were tested for fecal indicator bacteria (fecal coliforms, Escherichia coli and Enterococcus) and candidate swine-specific microbial source-tracking (MST) markers (Bacteroidales Pig-1-Bac, Pig-2-Bac, and Pig-Bac-2, and methanogen P23-2). Testing of 187 samples showed high fecal indicator bacteria concentrations at both up- and downstream sites. Overall, 40%, 23%, and 61% of samples exceeded state and federal recreational water quality guidelines for fecal coliforms, E. coli, and Enterococcus, respectively. Pig-1-Bac and Pig-2-Bac showed the highest specificity to swine fecal wastes and were 2.47 (95% confidence interval [CI]=1.03, 5.94) and 2.30 times (95% CI=0.90, 5.88) as prevalent proximal down- than proximal upstream of swine CAFOs, respectively. Pig-1-Bac and Pig-2-Bac were also 2.87 (95% CI=1.21, 6.80) and 3.36 (95% CI=1.34, 8.41) times as prevalent when 48hour antecedent rainfall was greater than versus less than the mean, respectively. Results suggest diffuse and overall poor sanitary quality of surface waters where swine CAFO density is high. Pig-1-Bac and Pig-2-Bac are useful for tracking off-site conveyance of swine fecal wastes into surface waters proximal to and downstream of swine CAFOs and during rain events.

Overcoming obstacles at the City of Raleigh’s Neuse River Wastewater Treatment Plant Land Application Site

Overcoming obstacles at the City of Raleigh’s Neuse River Wastewater Treatment Plant Land Application Site

Impact of Biosolids Recycling on Groundwater Resources

ABSTRACT: Using the United States Environmental Protection Agency's (U.S. EPA) Multimedia, Multi‐pathway, Multi‐receptor Exposure and Risk Assessment (3MRA) technology, a computer‐based biosolids groundwater risk characterization screening tool (RCST) was developed. The objective of this study was to apply the RCST to characterize the potential human health risks associated with exposure to biosolid pollutants. RCST application to two Virginia biosolids land application sites predicted that pollutant concentrations as large as ten times the current regulatory limit could be safely applied to land with no apparent human health effects associated with groundwater consumption. Only under unrealistically high biosolids application rates and pollutant concentrations were the public health risks associated with groundwater impairment characterized as significant (hazard quotient >= 1.0). For example, when the biosolids land application rate was increased to 900 Mg/ha and the pollutant concentrations were increased to ten times the legal limit, the hazard quotient value ranged from 1.27 (zinc) to 248.19 (selenium).

Land Application of Treated Sewage Sludge: Community Health and Environmental Justice

Background: In the United States, most of the treated sewage sludge (biosolids) is applied to farmland as a soil amendment. Critics suggest that rules regulating sewage sludge treatment and land application may be insufficient to protect public health and the environment. Neighbors of land application sites report illness following land application events.Objectives: We used qualitative research methods to evaluate health and quality of life near land application sites.Methods: We conducted in-depth interviews with neighbors of land application sites and used qualitative analytic software and team-based methods to analyze interview transcripts and identify themes.Results: Thirty-four people in North Carolina, South Carolina, and Virginia responded to interviews. Key themes were health impacts, environmental impacts, and environmental justice. Over half of the respondents attributed physical symptoms to application events. Most noted offensive sludge odors that interfere with daily activities and opportunities to socialize with family and friends. Several questioned the fairness of disposing of urban waste in rural neighborhoods. Although a few respondents were satisfied with the responsiveness of public officials regarding sludge, many reported a lack of public notification about land application in their neighborhoods, as well as difficulty reporting concerns to public officials and influencing decisions about how the practice is conducted where they live.Conclusions: Community members are key witnesses of land application events and their potential impacts on health, quality of life, and the environment. Meaningful involvement of community members in decision making about land application of sewage sludge will strengthen environmental health protections.

Groundwater quality protection at biosolids land application sites

Using the United States (US) Environmental Protection Agency's (EPA) Multimedia, Multi-pathway, Multi-receptor Exposure and Risk Assessment (3MRA) technology, a computer-based biosolids groundwater risk characterization screening tool (RCST) was developed. The RCST, which generates a non-carcinogenic human health risk estimate (i.e., hazard quotient or HQ value), has the ability to conduct screening-level risk-based characterization of potential human risks associated with pollutants released from biosolids land application sites. The HQ is a human health indicator that is equal to the ratio of the pollutant dose (mass of pollutant per unit body weight per time) to the specific pollutant reference dose (Rfd) which, in turn, is a human health benchmark defined by the EPA as a scientific estimate of the daily exposure level. A HQ value equal to or greater than one (1) suggests that the resulting conditions pose an unacceptable risk to human health.The focus of the current study was to evaluate whether the present regulatory limits established for biosolids pollutants (e.g., heavy metals) were sufficiently protective of human health associated with potential groundwater consumption using a new EPA risk assessment tool. Application of the RCST to two biosolids land application sites located near Columbus, Georgia predicted that, when the depth to groundwater was maintained at a distance of at least 2 m, regulated pollutant concentrations as large as ten (10) times the current regulatory limit (i.e., Title 40 of the US Code of Federal Regulations Part 503 – Ceiling Concentration Limit) could be safely land applied at rates as high as ninety (90) Megagrams per hectare (Mg ha−1) with no apparent non-carcinogenic human health effects associated with groundwater consumption. At these pollutant concentrations, the HQ ranged from 1.79 × 10−9 for cadmium to 3.03 × 10−3 for selenium.Only under unrealistically high biosolids application rates were the public health risks associated with groundwater impairment characterized as significant (HQ ≥ 1.0). For example, when the biosolids application rate was increased to 450 Megagrams per hectare (Mg ha−1) and the pollutant concentrations were increased to ten times the 40 CFR Part 503 Ceiling Concentration Limit, a HQ value of 2.23 was estimated (selenium). Similarly, when the biosolids application rate was increased to 900 Mg ha−1 and the pollutant concentrations were increased to ten times the regulatory limit, the HQ ranged varied from 1.4 (for zinc) to 324.0 (for selenium).

Surveillance and Investigation of the Illness Reported by Neighbors of Biosolids Land Application and Other Soil Amendments: Pilot Testing

In 2002, the National Research Council (NRC) completed an 18-month study entitled Biosolids Applied to Land: Advancing Standards and practices , which made an overarching recommendation to “establish a framework for an approach to implement human health investigations.” In response to this recommendation, the Water Environment Research Foundation (WERF) funded two projects. Phase I began in 2006 and WERF published the results in 2007. Phase I developed a draft five-step rapid response investigation protocol to collect data on reports of health effects from neighbors of land application sites. This project (Phase II) field tested and refined the Phase I draft protocol from May 2009 until November 2010, on 33 complaints from three states. The draft protocol included a health questionnaire to collect data on complaints of alleged health symptoms, nuisance odors, or quality of life effects from neighbors of land application sites of biosolids, manure and other materials, a generator questionnaire to characterize biosolids that were land applied and an applier questionnaire to document methods of application. The project team tested two site investigation reports which documented the location and described the land application site of concern. The project team also evaluated the health questionnaire using pre-testing, content expert reviews, and cognitive interviews during field testing, to determine if any biases existed within both the structure and organization of the questionnaire, the wording, and order of the questions, or within the methods of administration, such as measurement errors resulting from answers by respondents who misinterpreted or did not understand the meaning of questions. In addition, the project team evaluated the generator and applier questionnaires by pre-testing, content expert reviews, field testing, and by using a focus group of generators and appliers. The project team designed the protocol so that local or state public health departments and state biosolids regulators could apply it accurately, efficiently, and effectively as a component of a future standardized surveillance and “rapid response” investigation system throughout the country. The team of researchers also developed an outreach and implementation communication plan and a guidance document that suggested future research methods, based upon what the research team learned from this project. This title belongs to WERF Research Report Series . ISBN: 9781843396147 (eBook)

The relative effects of sodium and potassium on soil hydraulic conductivity and implications for winery wastewater management

The relative effects of Na+ and K+ on soil structural stability are not clearly defined by the existing literature. This is an important issue for the application of winery wastewater on soils as it contains high levels of K+ and varying levels of Na+. To evaluate the relative effects of Na+ and K+ on soil structural stability both surface and subsoil from a land application site for winery wastewater were used to assess changes in soil hydraulic conductivity in repacked soil columns. The soil was rich of smectite, 51–56%, with minor presence of illite, 5–8%, and kaolinite 10% clays. Solutions with sodium adsorption ratio (SAR) and potassium adsorption ratio (PAR) of 5–40, where the monovalent cation was Na+ or K+ and the divalent cation was Ca2+ or Mg2+ were used to leach the soil columns, at electrolyte concentrations ranging from 2.5 to 640meqL−1. In both surface and subsoil, percolating solutions with PAR or SAR, comprising all cation combinations, of 20 and 40 caused a decrease in hydraulic conductivity as electrolyte concentrations reduced. However, in PAR solutions the decreases in hydraulic conductivity were significantly smaller than the corresponding SAR solutions. These results indicated greater soil stability in the presence of K+ relative to Na+.

Occurrence, fate, and persistence of gemfibrozil in water and soil

Pharmaceuticals and personal care products (PPCPs) have emerged as a group of potential environmental contaminants of concern. The occurrence of gemfibrozil, a lipid-regulating drug, was studied in the influent and effluent at a wastewater treatment plant (WWTP) and groundwater below a land application site receiving treated effluent from the WWTP. In addition, the sorption of gemfibrozil in two loam soils and sand was assessed, and biological degradation rates in two soil types under aerobic conditions were also determined. Results showed that concentrations of gemfibrozil in wastewater influent, effluent, and groundwater were in the range of 3.47 to 63.8 µg/L, 0.08 to 19.4 µg/L, and undetectable to 6.86 µg/L, respectively. Data also indicated that gemfibrozil in the wastewater could reach groundwater following land application of the treated effluent. Soil-water distribution coefficients for gemfibrozil, determined by the batch equilibrium method, varied with organic carbon content in the soils. The sorption capacity was silt loam > sandy loam > sand. Under aerobic conditions, dissipation half-lives for gemfibrozil in sandy loam and silt loam soils were 17.8 and 20.6 days, respectively; 25.4 and 11.3% of gemfibrozil was lost through biodegradation from the two soils over 14 days.

Occurrence of synthetic musk fragrances in effluent and non-effluent impacted environments

Synthetic musk fragrances (SMFs) are considered micropollutants and can be found in various environmental matrices near wastewater discharge areas. These emerging contaminants are often detected in wastewater at low concentrations; they are continuously present and constitute a constant exposure source. Objectives of this study were to investigate the environmental fate, transport, and transformation of SMFs. Occurrence of six polycyclic musk compounds (galaxolide, tonalide, celestolide, phantolide, traseolide, cashmeran) and two nitro musk compounds (musk xylene and musk ketone) was monitored in wastewater, various surface waters and their sediments, as well as groundwater, soil cores, and plants from a treated wastewater land application site. Specifically, samples were collected quarterly from (1) a wastewater treatment plant to determine initial concentrations in wastewater effluent, (2) a storage reservoir at a land application site to determine possible photolysis before land application, (3) soil cores to determine the amount of sorption after land application and groundwater recharge to assess lack thereof, (4) a lake system and its sediment to assess degradation, and (5) non-effluent impacted local playa lakes and sediments to assess potential sources of these compounds. All samples were analyzed using gas chromatography coupled with mass spectrometry (GC–MS). Data indicated that occurrence of SMFs in effluent-impacted environments was detectable at ng/L and ng/g concentrations, which decreased during transport throughout wastewater treatment and land application. However, unexpected concentrations, ng/L and ng/g, were also detected in playa lakes not receiving treated effluent. Additionally, soil cores from land application sites had ng/g concentrations, and SMFs were detected in plant samples at trace levels. Galaxolide and tonalide were consistently found in all environments. Information on occurrence is critical to assessing exposure to these potential endocrine disrupting compounds. Such information could provide a scientific framework for establishing the need for environmental regulations.

Effects of tomato cannery water forage irrigation on nitrogen and carbon in a clay loam soil

Land application is a common method for treatment and disposal/reuse of process water and solids from food processing in Central Valley California, USA. Application rates are commonly based on N as contamination of ground and surface waters are of environmental concern. Contemporary disposal practices employ a crop to consume the N applied. Tomato processing wastewaters and semi-solid wastes were evaluated using homogeneous soil columns, and long-term monitoring of the cannery land application site. The 105-day outdoor column study included the smectitic field soil of clay loam texture, Bermudagrass, and three cannery water (CW) loading rates and a control (urea) applied weekly. NO 3 − and BOD leaching were low during the simulated irrigation season. Based on N grass uptake, leaching losses, and soil N, gaseous N losses were 50, 64, and 61% of the N applied from 313, 471, and 627 kg N ha −1 CW applications. However, gaseous N losses exceeded N applied by all treatments and included significant native soil N loss ranging from 1500 to 2600 kg ha −1. N losses indicated a “priming effect” due to mineralizable organics, and a significant decrease in soil C was seen in all treatments. The study results point toward denitrification as the major cause of gaseous N losses where ammonia volatilization was found to be a lessor cause of N loss. Long-term field monitoring results showed greater N impacts from land incorporation of semi-solid wastes than from wastewater irrigation, consistent with the soil column findings. The study demonstrated that CW having high amounts of labile organics applied to a soil of low permeability can result in heightened gaseous N loss rates, especially by denitrification. Gaseous N losses in addition to crop N uptake lessened the possibility of contamination of ground and surface waters.

Perfluorinated chemicals in surface waters and sediments from northwest Georgia, USA, and their bioaccumulation in Lumbriculus variegatus

Concentrations of perfluorinated chemicals (PFCs) were measured in surface waters and sediments from the Coosa River watershed in northwest Georgia, USA, to examine their distribution downstream of a suspected source. Samples from eight sites were analyzed using liquid chromatography-tandem mass spectrometry. Sediments were also used in 28-d exposures with the aquatic oligochaete, Lumbriculus variegatus, to assess PFC bioaccumulation. Concentrations of PFCs in surface waters and sediments increased significantly below a land-application site (LAS) of municipal/industrial wastewater and were further elevated by unknown sources downstream. Perfluorinated carboxylic acids (PFCAs) with eight or fewer carbons were the most prominent in surface waters. Those with 10 or more carbons predominated sediment and tissue samples. Perfluorooctane sulfonate (PFOS) was the major homolog in contaminated sediments and tissues. This pattern among sediment PFC concentrations was consistent among sites and reflected homolog concentrations emanating from the LAS. Concentrations of PFCs in oligochaete tissues revealed patterns similar to those observed in the respective sediments. The tendency to bioaccumulate increased with PFCA chain length and the presence of the sulfonate moiety. Biota-sediment accumulation factors indicated that short-chain PFCAs with fewer than seven carbons may be environmentally benign alternatives in aquatic ecosystems; however, sulfonates with four to seven carbons may be as likely to bioaccumulate as PFOS.

Assessment of the Soil Physical and Chemical Properties of Desert Soils Irrigated With Treated Wastewater Using Principal Component Analysis

The knowledge of soil heterogeneity is useful for designing site-specific soil management practices especially for those affected by anthropogenic activities. The objectives of this study were to identify and select the dominating soil factors and attributes caused by wastewater application for the management decisions of West Mesa land application site using the principle component analysis. Variability in soil properties was identified by coefficient of variation (CV) as the indicator. A property was ranked as least (CV < 0.15), moderate (0.15 < CV < 0.35) or most (CV > 0.35) variable using the criteria proposed by Wilding. Nitrate (NO3−), chloride (Cl−), sodium adsorption ratio, saturated hydraulic conductivity, sodium (Na+), and electrical conductivity were most variable in the irrigated plots at the 0- to 20-cm depth. The principle component analysis, which is widely used to reduce the dimensions of data, grouped 15 soil physical and chemical properties into four components (eigenvalue >1) soil sodicity, water transport, soil texture, and organic matter at the 0- to 20-cm depth and soil sodicity, soil texture, water retentiona and organic matter at 20- to 40-cm depth. Redundancy analysis showed that soil sodicity factor and Na+ as the most dominantly measured soil properties at both depths. Therefore, Na+ should be monitored over time in the West Mesa land application site. The mean sodium adsorption ratio for study site was 19.17 ± 2.92 in the irrigated plots, which is above the threshold limit for many plant species and may threaten the survival of woody and perennial herbaceous vegetation in the study area. Therefore, it is necessary to initiate management strategies for controlling soil sodicity in the West Mesa land application site.

A Strategic Risk Communications Process for Outreach and Dialogue on Biosolids Land Application

The long-term viability and sustainability of biosolids land application is dependent on continuously earning stakeholder confidence, trust and support. This requires ongoing and effective engagement and communication with key stakeholders about the beneficial use of biosolids in their communities. The goal of the risk communications research was to develop processes, tools and materials to help biosolids managers conduct effective outreach and dialogue with key stakeholders in the communities where they operate, first on biosolids land application and its beneficial use, then on specific challenges such as communicating about potential health risks due to pathogens in biosolids. The researchers developed a state-of-the-science Strategic Risk Communications Process, tools and materials that can be adapted and used by biosolids program managers. The Process was applied and validated through two case studies, which involved in-depth research with landowners who receive biosolids and neighbors to biosolids land application sites and, in one case, community health officials. The research demonstrated that the key influence on these stakeholders' judgments on the acceptability of biosolids land application is the trust they have in the people who are producing the product, the people who are using the product and the people are overseeing and ensuring the safe appropriate use of biosolids. These stakeholders recognized the benefits and risks associated with biosolids land application and support its beneficial use. However, their support was not unconditional - they had questions about the long-term health and environmental impacts of such application. The process, tools and materials developed through this project will serve to address these and other key questions, while enabling biosolids managers to continually build stakeholder support for biosolids land application. This title belongs to WERF Research Report Series . ISBN: 9781843392583 (Print) ISBN: 9781780403304 (eBook)

Spatial Variability of Electrical Conductivity of Desert Soil Irrigated with Treated Wastewater: Implications for Irrigation Management

Knowledge of spatial variability is important for management of land affected by various anthropogenic activities. This study was conducted at West Mesa land application site to determine the spatial variability of electrical conductivity (EC1:1) and suggest suitable management strategy. Study area was divided into five classes with EC increasing from class I to V. According to the coefficient of variation (CV), during 2009 and 2010, EC1:1values for different classes were low to moderately variable at each depth. Semivariogram analysis showed that EC1:1displayed both short and long range variability. Area coverage of classes I and II were much higher than classes III, IV, and V during 2009. However, during 2010 area coverage decreased from 26% to 14.91% for class II, increased from 12.11% to 22.97%, and 10.95% to 20.55 for classes IV and V, respectively. Overall area under EC1:1≥ 4 dS/m increased during 2009. Soil EC map showed EC classes IV (4.1–5 dS/m) and V (&gt;5.1 dS/m) were concentrated at northwest and southeast and classes I and II were at the middle of the study plot. Thus, higher wastewater should be applied in the center and lower in the northwest and southwest part of the field.

Biological Degradation of Common Pharmaceuticals and Personal Care Products in Soils with High Water Content

Biological degradation rates of six pharmaceuticals and personal care products were examined in soil from a land application site and in adjacent soil with no prior history of effluent exposure. Microbial degradation rates were compared over 2 weeks under standing water or saturated conditions and draining conditions after having been saturated for 3 days. Biological degradation of 17β-estradiol exhibited rapid rates of biological degradation under both saturated and draining conditions. Half-lives for 17β-estradiol ranged from 1.5 to 4 days; 66–97% was lost from the soils. Estriol showed a pattern of biological degradation in both saturated and draining conditions though the half-lives were longer (8.7–25.9 days) than those observed for 17β-estradiol. Twenty-eight percent to 73% of estriol was lost over the 14 days treatment period. Estrone and 17α-ethinylestradiol exhibited slower rates of biological transformation under saturated and draining conditions. Half-lives for estrone ranged between 27.5 and 56.8 days with loss of at most 21%. 17α-ethinylestradiol exhibited half-lives of 22.6–207 days. Half-life data for ibuprofen ranged from 30.4 to 1,706.4 days in this experiment. Losses of up to 17% were observed in draining soils. Triclosan loss was at most 10%, and half-lives were 70.9–398.8 days. In all cases, soils that were draining from saturated conditions exhibited faster degradation rates than soils that remained saturated. Prior exposure of the soil to effluent did not always result in higher biological degradation rates.