Project Overview

Full Title
Evaluation of the Impact of Biosolids Application Fields on Surface-Water Loads and Groundwater Quality in the Jordan Lake Watershed, North Carolina

Location
  Orange County

Cooperating Agencies
North Carolina Non-point Source 319 Grant Program

Project Chief
Chad Wagner

Period of Project
2011 - 2014

Team Members
Sean Egen
Kristen McSwain
Ryan Rasmussen
Steve Harden

Science Topic
Agriculture and Water Quality
Support of Federal and State Programs

USGS IN YOUR STATE

USGS Water Science Centers are located in each state.

Effects of land-applied biosolids on water quality in the Jordan Lake Watershed

Project Summary

Biosolid application field in Orange County, North Carolina

Background

Biosolids are defined as any solid, semi-solid, or liquid waste, other than effluent or residues from agricultural products and processing, generated from a wastewater treatment facility, water supply treatment facility or air pollution control facility permitted under the authority of the Environmental Management Commission (EMC). Depending upon the level of treatment that the biosolids receive, the generator may land apply the biosolids for livestock feed or dispose of the biosolids in a surface disposal unit (i.e. land fill, incineration). The practice of applying biosolids from municipal wastewater treatment plants to agriculture fields is becoming commonplace across much of the Piedmont and Coastal Plain of North Carolina. As of December, 2009 a total of 260 facilities (5,145 fields comprising 107,200 acres) were permitted to land apply biosolids in North Carolina and 15 facilities were permitted for surface disposal.

Land application of municipal wastewater biosolids is the most common method of biosolids management used in North Carolina and in the United States. Biosolids have some characteristics that can be beneficial to soil and plants, and thus land application can take advantage of the beneficial qualities; whereas disposal in landfills or incineration poses no benefits or use of the waste. For these reasons, the State of North Carolina and the U.S. Environmental Protection Agency (EPA) consider controlled land application a 'beneficial use' of biosolids. However, some independent studies (U.S. Environmental Protection Agency, 2009; National Research Council of the National Academy of Sciences, 2002; and Rudo, 2005) have shown that biosolids can pose a threat to human health as well as surface water and groundwater quality. Hence, under North Carolina General Statue (NCGS) biosolids are defined as waste (NGCS 142-213) and any system that collects, treats, or disposes of waste cannot be constructed or operated without a permit (NCGS 143-215.1(a)). The statute authorizes the EMC and the Department of Environment and Natural Resources (DENR) to develop and implement state regulations and issue permits for the generation and disposal of residuals, however only DENR's Division of Water Quality (DWQ) carries out these functions. The North Carolina rules for biosolids management meet or exceed the Federal 40 Code of Federal Regulations (CFR) 503 standards for the use or disposal of biosolids.

NC Division of Water Quality (DWQ) implements a permitting strategy that is designed to assure that relevant information is available to concerned parties before, during and after application of biosolids in an attempt to assure that land applications of biosolids are managed safely and effectively. DWQ conducts regional and central office reviews of all permit applications and conducts site visits to proposed fields to verify conditions and works with County Managers and County Health Departments to address local concerns with proposed land application activities. Permit holders are required to submit an annual report summarizing the past years activities and documenting that biosolids quality and nutrient management requirements were met. Permit holders are responsible for meeting the requirements of their permit and to report any violations. Monitoring and enforcement of permit requirements is challenging and relies primarily on citizen complaints and self reporting of permittees. There are no consistent guidelines on groundwater and surface water monitoring at biosolids land-application sites before problems arise. Many monitoring requirements are the result of complaints or evidence of impacts to waters of the State after contamination has occurred. A better understanding of the quantity and characteristics of nutrients, bacteria, metals and emerging contaminants that are transported away from biosolids fields to surface water and groundwater resources would provide the framework for developing guidance on effective techniques for monitoring and regulatory enforcement of permitted biosolids land application fields.

Objective

The primary objective of this investigation is to initiate a paired agricultural watershed study designed to better understand transport of nutrients and bacteria from biosolids application fields to groundwater and surface water. Results will be useful for developing and implementing Total Maximum Daily Loads(TMDLs) for nutrient-impaired watersheds and to provide a scientific basis for evaluating the effectiveness of the current regulations. The proposed study primarily focuses on nutrients and bacteria because these are priority constituents for the 319 Program and because the study area is included in a nutrient TMDL. Data for other water-quality constituents including field parameters, metals, major ions, and organic wastewater compounds, will be collected and used to characterize the potential impact of land applied biosolids to groundwater and surface water.

The objectives for this investigation are as follows:

1. Assess the offsite transport of nutrients and bacteria in groundwater and overland runoff from the biosolids application fields to receiving streams;
2. Compute and compare surface water nutrient and bacteria loads for both a watershed with biosolids land application and a nearby watershed without biosolids application;
3. Perform preliminary evaluation of organic wastewater compounds as potential indicator of Wastewater Treatment Plant (WWTP) residual biosolids derived constituents in surface water and groundwater; and
4. Analyze and summarize the data to characterize impact of land applied biosolids on groundwater and receiving surface water.

Scope

This work will be conducted in cooperation with NC Division of Water Quality (DWQ) in the Collins Creek and Cane Creek Reservoir watersheds in Orange County, North Carolina. The scope of work for this proposal extends over a 3-year period, beginning in January 2011 and ending in March 2014.

Field data collection activities are being conducted during the first two years. Field activities are being conducted at two field study sites, including biosolids field application sites owned by Orange County Water and Sewer Authority (OWASA) on Collins Creek and a background study site on Cane Creek that has no fields receiving biosolids applications. At the Collins Creek biosolids field application sites, samples of biosolids source material and soil will be collected in the application fields for laboratory analyses. Groundwater samples will be collected for laboratory analyses, from new monitoring wells and(or) drive points installed by NCDENR, along the edge of biosolids application fields. Two surface-water sites (upstream and downstream of thebiosolids application fields) were established on Collins Creek to monitor water-quality conditions adjacent to the biosolids application study site. Surface-water samples also will be collected to monitor water-quality conditions at the background study location on Cane Creek. An existing USGS stream gage on Cane Creek (Station number 02096846) will be used to document streamflow at the Cane Creek site. Groundwater samples will also be collected from new monitoring wells and(or) drive points installed by NCDENR along the edge of agricultural fields that have never had land application of biosolids for laboratory analyses.

Samples of source material, soil, surface water and ground water will be analyzed primarily for nutrients, major ions, metals and fecal-coliform bacteria. As part of this 319 project, preliminary sampling of biosolids source material from the application fields and surface water at the Collins Creek upstream and downstream application sites, as well as the Cane Creek background site, will be conducted for analysis of organic wastewater compounds (OWCs), including such things as household, industrial, and agricultural-use (HIA) compounds, pharmaceutical compounds, hormones, and antibiotics. In the final year of the project, the USGS will work collaboratively with NCDENR to develop a final project report that evaluates the study.