This article is part of a series designed to share the experience and lessons learned by Rural Clean Water Program (RCWP) project personnel by highlighting some of the projects' Ten- Year Reports.

Oakwood Lakes - Poinsett RCWP Project Team

Project Synopsis

Corn, soybeans, alfalfa, and small grains are the major crops produced in the project area.

The identified water quality problems were: 1) elevated trace levels (exceeding the drinking water standard of 10 milligrams per liter) in certain areas of the Big Sioux aquifer and 2) high nutrient levels in the lakes through delivery by the intermittent tributaries.

RCWP contracts covered 48,088 acres, representing 60% of the critical area as originally defined and 81% of the highest priority portion of the critical area.

Project Objectives and Goals

The goal of the Comprehensive Monitoring and Evaluation (CM&E) phase was to monitor the effects and evaluate the impacts to ground and surface water from the implementation of BMPs.

Project Administration and Coordination

Best Management Practices Implemented

Selected Findings and Recommendations

General

• Producer participation was high, with a majority of farmers maintaining BMPs after the cost share period ended.

• Cost share is the most important incentive for adoption of BMPs and project participation

• Cooperation among the participating agencies was outstanding, with all the agencies maintaining an active involvement throughout the project.

• Development of formal and informal lines of communication increased effectiveness of the interdisciplinary and interagency teams.

• Project leadership should come from a full-time person from one of the project agencies on temporary assignment of at least half-time as project coordinator. This person would be responsible for facilitating and coordinating communication between the local and state coordinating committees and technical teams. The coordinator would provide leadership for a project management team representing each of the active participating agencies to keep the project on track

• The project coordinator was an important link between the coordinating committees, the land treatment team, and the CM&E team. The project coordinator position was most effective when the coordinator's office was located near the project area.

• All participating agencies should be involved in the development of a joint work plan which includes a unified reporting system and the allocation of resources. Formal agreements should e)dst but be flexible and supportive of the joint work plan.

• Pre-project data and modeling should be used to quantify the goals of the project The water quality problem, the value of the resource, and the magnitude of the pollution source must be clearly identified in order to develop attainable goals and objectives.

• Project areas should be of manageable size with baseline land use and farm management data available so that conservation management systems (combinations of BMPs) can be developed to minimize pollution and protect water quality m the area.

• The project must have an impact on the water resource, must have adequate funding, and must be acceptable to the producers if project objectives are to be achieved. Deficiencies in any one of these factors should result in reconsideration of the project.

Information and Education (I&E)

• The I&E program was essential for the successful completion of the project.

• Following mass media and public meetings to create an awareness, direct one-to-one contact with producers provided an excellent mechanism for producer participation, conservation planning, and BMP implementation.

• National and state publicity on occurrences of ground water contamination by nitrate and pesticides positively impacted the formulation and implementation of the RCWP activities. CM&E project findings about the extent and cause of nutrient, pesticide, and sediment contamination were therefore rapidly incorporated into the project I&E program and statewide I&E water quality programs. This has influenced state policy, regulation, and research in water quality protection.

• Results of an SCS questionnaire indicated that the primary source of project information to producers was word of mouth (32%). Other sources were SCS (30%), ASCS (23%), and newsletters and news releases (14%).

• An I&E committees- consisting of representatives of cooperating agencies should be responsible for developing and implementing an I&E program A general I&E work plan for the duration of the project should be developed to provide a strategy and guidance. The chair of this committee should be a member of the SCC.

• An annual evaluation of the I&E program and review of the work plan should be conducted by the I&E committee to identify specific activities and needed materials, responsible agencies/persons, and a timetable for completing activities. The SCC should participate in the evaluation and review and approve the updated work plan.

• To assist in the evaluation of the project, pre- and post-project surveys of residents of the project area to determine changes of attitude are recommended.

• The I&E strategy must identify specific audiences and their needs, prioritize objectives, set measurable goals, and develop delivery programs that enable the producers to attain water quality goals. The strategy should be adjusted as the project progresses.

• Educational programs similar to pesticide applicators training should be used to incorporate water quality into the farmer's decision-making process.

Water Quality

• The water quality monitoring indicated that implementation of BMPs that protected and improved the surface water quality did not adversely impact the ground water quality.

• Pre-project monitoring data are essential in problem identification, setting goals and objectives, and targeting of effort.

• The involvement of national technical experts assisted in the development of a sound monitoring and implementation program.

• Sampling schedules should be flexible to detect changes in water quality attributable to runoff or leaching events.

• Nested monitoring wells are recommended to adequately describe the variability of the ground water quality with depth

• Monitoring of farm-field scale sites is necessary to identify water quality problems and determine relationships between land surface activities and water quality but is not sufficient to describe cause and effect mechanisms. In contrast, smaller scale laboratory plots and experiments are better suited to identify the cause and effect mechanisms.

• The presence of nitrates as a contaminant in the ground water was more pervasive than pesticides at the field sites evaluated. Both contaminants were found in the upper portions of the water-bearing materials. All field sites had at least one sample with nitrate concentrations greater than 10 ppm as nitrogen.

• The three major influences on nitrate concentrations in the ground water are 1) the amounts of fertilizer applied (related to crop), 2) precipitation/infiltration events, and 3) denitrification.

Best Management Practices

• Water quality monitoring and land treatment personnel should work closely in the early stages of a project to insure BMPs are appropriate to improve or protect the targeted resource, whether surface or ground water.

• Weather, economic conditions, and other government programs impacted the BMP sign-ups.

• Conservation tillage and fertilizer and pesticide management were the major BMPs implemented by participants because these BMPs were easy to apply and profitable for producers. Animal waste management systems were not well accepted by producers in the project area.

• One-on-one contact focused on high priority areas enhanced BMP implementation however, RCWP personnel turnover made it difficult to maintain continuity with participants.

• Base line land use and agricultural management data for the project area should be collected and analyzed to identify high priority areas prior to implementation of BMPs.

• A more detailed understanding of the mechanisms of water and contaminant transport derived from repeatable experiments is needed to develop more effective BMPs.

For Further Information

Assessment of Environmental and Economic Effects of
Nonpoint Source Pollution Controls
in the Herrings Marsh Run Demonstration Watershed
Using Geographic Information Systems and Nonpoint Source Modeling

Introduction

Demonstration Project personnel are using educational programs in addition to technical and financial assistance to encourage agricultural producers in the watershed to implement best management practices (BMPs). The environmental and economic effectiveness of these efforts is being assessed through the use of monitoring and modeling. Results of these analyses will be used in planning future Coastal Plain agricultural NPS control projects so that they may be conducted more efficiently.

The Herrings Marsh Run USDA Water Quality Demonstration Project makes extensive use of a geographic information system (GIS) to manage water quality and economic data obtained from monitoring and modeling and to identify critical areas for NPS control implementation and study. In tills article we will:

• Describe the environmental and economic data collection and management system,

• Describe NPS modeling being planned and conducted, and

• Demonstrate the use of GIS to identify critical areas in the project watershed in order to target BMP implementation efforts, target water quality monitoring efforts, and evaluate the cost-effectiveness of water quality improvement efforts.

Background

Duplin County has the highest estimated gross agricultural revenue ($331 million 1991) in the state, nearly 80% of which is derived from poultry and swine production. The county ranks first nationally in turkey population and fourth in hog population. The Herrings Marsh Run Watershed typifies the diverse agriculture practiced in Duplin County and southeastern North Carolina. There are 120 farms in the 5,050-acre watershed, with 2,700 acres of cropland. Other land uses include 1750 acres of woodland, 525 acres of home sites and farmsteads, and 75 acres of highways and right-of-ways.

Crop production in the watershed consists of various crops grown under several different crop rotation systems. Major crops are tobacco, corn, soybeans, cotton, wheat vegetables, and coastal bermuda grass. In addition, some acreage is used for pasture and hay production by livestock producers. Typical forage crops are hybrid bermuda grass overseeded with rye during winter months. Fescue is grown in some low-lying areas.

Annual nutrient use is estimated at 132 tons of nitrogen 58 tons of phosphorus, and 221 tons of potassium. Animal waste generated in the watershed contains enough nutrient value to supply approximately half of the required nutrients. However, most crop nutrients have historically been purchased as mineral fertilizers. For example, nitrogen from fresh animal manure is available to supply an estimated 40 pounds per acre of plant-usable nitrogen to all farmable land. However, an estimated 98% of nitrogen used for crop production has been purchased in mineral form. Pesticide use is extensive in the watershed, with about 50 different chemicals being used. Certain crops require multiple applications of various pesticides. For example, cotton typically receives up to 15 applications of 14 different pesticides.

Preliminary stream grab sampling at five sites in 1990 indicated relatively high levels of nitrogen, phosphorus, and suspended solids. These data indicated there was potential for surface water quality improvements through implementation of BMPS. A private well sampling program was conducted in the Herrings Marsh Run Watershed in 1990 in which over 90% of the 250 residential wells were analyzed for nitrate and four commonly-used pesticides. Results indicated that one-fifth of residential wells contained nitrate-nitrogen at levels exceeding the 10 ppm drinking water standard. The distribution of high- nitrate wells was scattered throughout the watershed. In addition, over one- third of the wells contained pesticide residues. The most com- monly detected pesticides were atrazine and alachlor, each detected in one-fifth of the wells. A detailed survey of residential well construction and protection showed that most water supply wells in the region are poorly constructed and shallow (less than 25 m in depth).

The land use, physical characteristics, and documented potential for water quality improvements in the Herrings Marsh Run Watershed make it ideal for targeting BMP implementation efforts. Extensive monitoring and modeling of water quality and economic returns will allow for assessment of the effectiveness of this USDA program in meeting water quality objectives while maintaining or increasing farm profitability.

Data Collection and Management

Environmental Factors

Agricultural Production Practices

Producer surveys are being used to track land use and land treatment activities at the soil mapping unit (SMU), field, and watershed levels. Separate surveys for cropping and production systems are used. A Cooperative Extension Service technician completes surveys during annual interviews with producers, during which time farm records are reviewed. Cooperation is excellent with 69 of the 70 producers in the watershed participating.

The cropping system survey is designed to be useful in making nutrient and pesticide recommendations. Separate surveys are completed for each field. Fields are identified by ASCS tract number, farm number, and field number. Soil mapping units and SCS leaching indexes are recorded along with soil, tissue, and waste analysis results; application rates of nutrients and pesticides; tillage practices; seeding rates; and application of nutrients and pesticides. Five-year crop and yield histories are also obtained, along with descriptions of BMPs employed, their cost, and their funding sources. The animal system survey tracks production rates, feed consumption, and waste generation for each enterprise. Details of the waste management systems are recorded.

Water Quality Monitoring

Continuous monitoring at the four stream sampling sites is conducted by ARS. Water quality samples are collected hourly and combined into eight-hour composite samples for analysis for nitrate, nitrite, ammonium, total kjeldahl nitrogen, total phosphors, and orthophosphate. Stream discharge is recorded by USGS. Sites are located at the watershed exit, upstream from the exit, below an area of intensive crop and animal agriculture, and in a background area with relatively few potential inputs upstream. Preliminary results from stream monitoring indicate higher concentrations of nitrogen and phosphorus at the site below intensive crop and animal agriculture than at other locations. Biological monitoring is conducted annually at this site by the DEM. Benthic macroinvertebrates are collected using DEM's standardized quantitative collection techniques.' Aquatic fauna are inventoried, with the primary output consisting of a species list with indications of relative abundance (rare, common, abundant) for each taxon. Unstressed streams have a diversity of species, while stressed streams have relatively few species. Water quality ratings are assigned based on the abundance and characteristics of the most intolerant invertebrate groups. Potential stream bioclassifications are excellent good, good/fair, and fair. Baseline biological monitoring data from 1990 indicate a bioclassification of fair. Biological sampling at this site and two additional sites will be repeated annually.

Monitoring wells are located to evaluate impacts of specific land use practices on shallow ground water quality. Plastic wells ranging in depth from 8 to 12 m are monitored monthly for nitrate-nitrogen. Some wells are monitored for pesticides on a less frequent basis. Current well field sites include a swine waste irrigation field, pasture land onto which turkey mortality compost is applied, cropped areas for which nutrient and pest management practices are being implemented, and the site of a turkey mortality composter.

Private water supply wells are sampled annually for nitrate-nitrogen and pesticides.

Data Management

Nonpoint Source Model Application

Field data from soil cores and monitoring wells in the watershed will be used to select calibrate, and validate appropriate models. Field data and error analysis procedures will be used to establish model inputs and to improve loading estimates derived from the models. Models calibrated in the Herrings Marsh Run Watershed will be tested for nearby watersheds using limited monitoring data to assess transferability throughout the Coastal Plain region.

The producer survey conducted by CES will track land use and land treatment activities for five years at the SMU, field, and watershed levels. A GIS will be used to manipulate and present data on land use, land treatment costs, and returns for various unit areas. Data will be aggregated upward to estimate economic and ground water impacts at the SMU, field, and watershed levels.

At the completion of the project, selected policy alternatives will be evaluated for their impacts on farm practices, net returns, and water quality. Policy alternatives will include cost-sharing and other economic incentives to adopt BMPs, limits to the quantity of selected contaminants that may be applied to critical areas, and other policies appropriate for consideration. Detailed farm practice and economic data collected in the Herrings Marsh Run Watershed will provide a baseline from which to calculate economic response and effects of policy alternatives. An economic optimization model will be used to identify farm practices that maximize net returns while meeting constraints imposed by site conditions, past production capabilities, physical relationships represented in models, and policy-imposed constraints. Policy-induced economic impacts for SMU, field, and watershed levels will be identified as changes in net returns.

Application of GIS for Critical Area Determination and Project Evaluation

One application of GIS in identifying critical areas for targeting education efforts is the location of contaminated private water supply wells. Contaminated wells or wells located near potential contamination sources are determined on a map, providing a useful tool for determining patterns of ground water contamination. The map also provides a valuable educational tool for showing residents how their wells may be contaminated because of their location in relation to nearby sources. Areas where clusters of contaminated wells are observed are targeted for further inves- tigation.

GIS can also be used to target areas for pesticide or nutrient management strategies. A combination of factors can be analyzed, including soil properties, pesticide or nutrient application rates, and practices for handling agrichemicals determined from the farm surveys. These data are supplemented by monitoring and modeling results to assist in validating procedures. After the procedures are refined and tested in the project area, they will be extended to other regions within the Coastal Plain.

Targeted areas can be soil mapping units (SMU), fields, or watersheds. The Herrings Marsh Run Watershed is divided into several sub-basins for analysis within and between regions. Corresponding to the field identification numbers in the data base are all the data collected from the farm surveys and other sources. These data are combined and analyzed to determine critical fields for study.

To target fields for integrated crop management (ICM) based on their potentials for causing ground water contamination, pesticide and nutrient application histories along with soil leaching indexes are analyzed. After identifying fields with high potentials for leaching, well testing results are analyzed to verify potential critical areas. Crop fields considered susceptible to leaching and near wells with pesticide detections or high nitrate levels are targeted for ICM. Similarly, to target fields for improved animal waste management (soil and waste testing, irrigation scheduling, application at agronomic rates), fields receiving animal waste with high leaching indexes are identified. Then results of well testing are used to further refine the analysis. Fields near high-nitrate wells are targeted for improved animal waste management practices.

Following completion of BMP implementation and monitoring, overall project effectiveness and cost-effectiveness win be evaluated and reported. Net returns based on economic optimization models will be correlated with water quality impacts for each unit area. GIS will be used to categorize areas with varying net returns and water quality impacts. Results will be grouped into "best-case, " "worst-case," and "mixed-results" scenarios. In the "best-case" scenario, net returns increase or are maintained, while water quality improves or is maintained. Results are reversed in the "worst-case" scenario. Other cases result in "mixed-results" scenarios. Optimal educational financial and technical programs to reduce agricultural pollution will be identified at the end of the project using this analysis.

The USDA Water Quality Program Plan requires an evaluation of the performance of this FY1990-94 program. To implement the Program Plan, the Education, TechnicaL and Financial Assistance (ET&FA) Committee of the USDA Working Group on Water Quality developed the conceptual framework. Three USDA agencies - Economic Research Service, Extension Service, and Soil Conservation Service (SCS) -- are responsible for evaluating the ET&FA program from a national perspective. The evaluation has four components: 1) Initial Organization and Implementation, 2) Producer Adoption, 3) Physical Impact Assessment and 4) Economic Assessment.

In May, 1992, USDA-SCS published a report on component 3: Physical Impact Assessment, presenting the approach being taken to assess the ability of USDA projects to protect or improve water quality from agricultural nonpoint source pollution and to document that protection or improvement. The approach emphasizes training project staff in the use of monitoring and physical process stimulation techniques to better document progress.

The report gives a brief overview of the full ET&FA evaluation, the Assessment approach, a description of the 16 projects participating in the Assessment technical assistance plans of the Assessment team for FY 1992, and an outline of the Interim Report to be issued in March of 1993.

Copies of the report may be obtained by contacting John D. Sutton, Strategic Planning and Policy Analysis, USDA-ASCS, Room 6168-S, P.O. Box 2890, Washington, DC 20013, Tel: (202) 720-0122.

NWQEP NOTES is issued bimonthly. Subscriptions are free (contact: Publications Coordinator at the address below or via email at wq_puborder@ncsu.edu). A list of publications on nonpoint source pollution distributed by the NCSU Water Quality Group is included in each hardcopy issue of the newsletter.

I welcome your views, findings, information, and suggestions for articles. Please feel free to contact me.

Judith A. Gale, Editor
Water Quality Extension Specialist
North Carolina State University Water Quality Group
Campus Box 7637
North Carolina State University
Raleigh, NC 27695
Tel: 919-515-3723
Fax: 919-515-7448
Internet: notes_editor@ncsu.edu