The NCSU Water Quality Group Newsletter
Number 77 May 1996 ISSN 1062-9149
The following article describes an on-going BMP-effectiveness monitoring program being conducted in Otter and Halfway Prairie Creeks by the U.S. Geological Survey (USGS), in cooperation with the Wisconsin Department of Natural Resources. In addition to being part of the state's Nonpoint Source Water Pollution Abatement Program, Otter Creek is also the site of a Section 319 National Monitoring Program (NMP) project. Monitoring for the Otter Creek 319 NMP Project (see article in NWQEP NOTES No. 69, January 1995) is also being conducted by the USGS.
Todd D. Stuntebeck, U.S. Geological Survey
The U.S. Geological Survey, through a cooperative effort with the Wisconsin Department of Natural Resources, is monitoring water-quality improvements that result from the implementation of BMPs in priority watersheds. As part of this effort, the USGS is evaluating the effectiveness of barnyard-runoff control BMPs implemented at two barnyards, one each on Otter Creek and Halfway Prairie Creek (Figure 1). A sloped concrete apron and retaining wall were added to the barnyard at Otter Creek. The structure directs runoff into a screened collection box, from which wastewater is gravity-piped to a concrete settling pad that evenly distributes the runoff onto a grassed filter strip. A similar runoff-control system has been implemented at Halfway Prairie Creek. The BMPs being evaluated were designed according to National Resource Conservation Service engineering standards by county Land Conservation Department staff. Post-BMP sampling will begin in spring or summer of 1996, and will continue through the summer and fall. The water quality data collected will be compared to the watershed plans to assess progress and determine whether goals are being realized.
This article describes the data-collection efforts, preliminary results, and planned data-analysis techniques of the monitoring programs at Otter and Halfway Prairie Creeks.
Figure 1: Location maps showing the upstream and downstream stations for Halfway Prairie Creek and Otter Creek and the location of the two projects within the state of Wisconsin.
Otter Creek is within the Sheboygan River Priority Watershed, 15 miles west of Lake Michigan, in east-central Wisconsin (Figure 1). The drainage area of Otter Creek is 9.2 square miles at the downstream sampling station, and land use in the watershed is 67% agricultural (Bachhuber and Foye, 1993). Upstream and downstream sampling stations, each of which are equipped to continuously monitor streamwater levels and collect discrete water samples, were installed at Otter Creek in March 1994. Water samples are collected with a refrigerated water-quality sampler that is activated by the rise and fall of streamwater levels.
Halfway Prairie Creek is within the Black Earth Creek Priority Watershed, 20 miles northwest of Madison, in south-central Wisconsin (Figure 1). The drainage area of Halfway Prairie Creek is 16.1 square miles at the downstream sampling station, and land use in the watershed is 60% agricultural (Eagan and Morton, 1989). Upstream and downstream sampling stations were installed at Halfway P rairie Creek in April 1995. The upstream sampling station continuously monitors streamwater levels and precipitation and collects discrete water samples with a refrigerated water-quality sampler. The downstream station is equipped to collect water samples only.
Upstream-downstream sampling schemes have the inherent potential for upstream loading sources to mask the effects of the investigated source, because individual inputs are often small compared to the cumulative inputs from upstream (Spooner et al., 1985). To reduce the potential for this problem, project investigators added two enhancements to the sampling design used at Otter Creek in order to improve the isolation of barnyard runoff at Halfway Prairie Creek. First, the water-quality samplers are activated by precipitation and are programmed to collect time-integrated samples for an initial period. This enhancement will be added to the Otter Creek sampling design for the post-BMP monitoring period. Samples are then collected in response to the rise and fall of streamwater levels in a manner similar to that at the Otter Creek stations.
Two benefits of this approach are that 1) it allows for sampling of barnyard runoff in the receiving stream before streamwater level increases can be sensed, thereby effectively isolating the barnyard runoff from nonpoint-pollution sources upstream and 2) it allows sampling during small storms in which local inputs from the barnyard are apparent, but little storm runoff from the upstream areas of the watershed is observed. A second enhancement to the Otter Creek sampling design is that the upstream and downstream stations at Halfway Prairie Creek are located close enough together to allow a direct electronic connection and, hence, the collection of concurrent samples from both water-quality samplers. This design allows for statistical comparisons between concurrent individual upstream and downstream concentrations in water samples.
Samples of streamflow were collected during 10 storms between April 1994 and June 1995 at Otter Creek, and 10 storms between April and June of 1995 at Halfway Prairie Creek. Samples were analyzed for total phosphorus, ammonia nitrogen, biochemical oxygen demand (BOD), suspended solids, and fecal coliform bacteria. All are known to be potential indicators of nonpoint pollution from barnyards.
In general, event-mean concentrations of total phosphorus, ammonia nitrogen, and BOD were greater at the downstream station than at the upstream station for most periods of storm runoff at Otter Creek (Figure 2). Using a paired Student's t-test, it was determined that for each constituent, the average of the differences between upstream and downstream event-mean concentrations was significantly different from zero at the 95-percent confidence level. In other words, average downstream event-mean concentrations of total phosphorus, ammonia nitrogen, and BOD were significantly greater than average upstream event-mean concentrations . The statistically significant increases in event-mean concentrations downstream from the barnyard suggest that the investigated barnyard-runoff source is an important contributor to the concentrations of total phosphorus, ammonia nitrogen, and BOD in Otter Creek for the storms monitored.
Figure 2: Event-mean concentrations and runoff volume for selected storms, Otter Creek, Wisconsin.
Event-mean concentrations of total phosphorus, ammonia nitrogen, and BOD downstream from the barnyard on Halfway Prairie Creek were also generally higher than those upstream (Figure 3). Average downstream event-mean concentrations of total phosphorus, ammonia nitrogen, and BOD were significantly greater than average upstream event-mean concentrations at the 95-percent confidence level. Differences between upstream and downstream event-mean concentrations at Halfway Prairie Creek were less variable than those at Otter Creek. Time-integrated samples collected early in the storms at Halfway Prairie Creek may have helped to isolate barnyard runoff from other upstream sources of pollution loads. Similar runoff volumes among the storms and minimal seasonal changes between storms also may explain this lower variability.
Figure 3:Event-mean concentrations and runoff volume for selected storms, Halfway Prairie Creek, Wisconsin.
Using the Student's t-test to find differences between two independent data sets, one can develop an equation for estimating the minimum amount of decrease in post-BMP downstream event-mean concentrations necessary to be considered statistically significant. This "minimum detectable change" is usually expressed as a percentage. If the pre- and post-BMP sample sizes are assumed to be equal (10 storms) and the variance in the differences between upstream and downstream concentrations is kept constant, minimum detectable changes for significance at the 95-percent confidence level are the following:
_____________________________________________________________________________
MINIMUM DETECTABLE CHANGE
Creek Total Ammonia BOD
Phosphorus Nitrogen
_____________________________________________________________________________
Otter 50 50 40
Halfway Prairie 10 30 40
_____________________________________________________________________________
To clarify, the average downstream post-BMP event-mean concentrations of total
phosphorus at Otter Creek would have to decrease by at least 50% for the change
to be considered statistically significant at the 95-percent confidence level.
These values are conservatively high because variance in the downstream-upstream
differences for average pre- and post-BMP event-mean concentrations was assumed
to remain constant. One would expect the actual variance to decrease after BMP
implementation, thus decreasing the minimum detectable changes. As discussed
earlier, the differences in event-mean concentrations between upstream and
downstream samples for Halfway Prairie Creek were less variable than those for
Otter Creek. This is reflected in lower minimum detectable changes. According
to the watershed plans (Bachhuber and Foye, 1993; Eagan and Morton, 1989), the
minimum detectable changes are smaller than the pollutant reductions expected
from BMP implementation at each site.
Copies of the fact sheet, Evaluating Barnyard Best Management Practices in Wisconsin Using Upstream-Downstream Monitoring, may be requested (free) from the National Water Information Center, 427 National Center, Reston, VA 22092, Tel: 800-426-9000. T he fact sheet is accessible on-line at http://wwwdwimdn.er.usgs.gov/widocs/pubs/pubs.html.
Eagan, L.L., and A. Morton. 1989. A Plan for the Control of Nonpoint Sources and Related Resource Management in the Black Earth Creek Priority Watershed. WI Dept. of Nat. Resources Publication WR-218-89.
Porterfield, G. 1972. Computation of Fluvial-sediment Discharge: U.S. Geological Survey Techniques of Water-Resources Investigations, book 3, chapter C2, 66 p.
Spooner, J., R.P. Maas, S.A. Dressing, M.D. Smolen, and F.J. Humenik. 1985. Appropriate Designs for Documenting Water Quality Improvements from Agricultural NPS Control Programs, Perspectives on Nonpoint Source Pollution. U.S. Environmental Protection Agency, Washington, DC, EPA 440/5-85-001, p. 30-34.
Proceedings of the Third National Nonpoint Source Watershed Monitoring Workshop, held in Seattle, Washington, October 2-6, 1995, have been published by the U.S. Environmental Protection Agency. Papers address project planning and management, institutional and social issues, cooperative efforts, water quality and data evaluation, nonpoint pollution sources, spatial analysis of data, biological monitoring, monitoring designs, land treatment monitoring, linking land treatment with water quality at the watershed level, and statistical concepts and applications.
The proceedings may be requested (free) from the Publications Coordinator, NCSU Water Quality Group, Suite 100, 615 Oberlin Road, Raleigh, NC 27605-1126, Fax: 919-515-7448, email: wq_puborder@ncsu.edu
The video ($30, including shipping) may be ordered from Publications Orders, Ag.
Communications, OSU, Admin. Services Bldg A422, Corvallis, OR
97331-2119, Tel: 503-737-2513, Fax: 503-737-0817.
Woodside, M.D. and B.R. Simerl. 1995. National Water-Quality Assessment
Program -- Land Use and Nutrient Concentrations and Yields in Selected Streams
in the Albemarle-Pamlico Drainage Basin, North Carolina and Virginia. Open-File
Report 95-457. U.S. Geological Survey, Raleigh, NC. 4p.
McMahon, G. and O.B. Lloyd. 1995. Water-Quality Assessment of the
Albemarle-Pamlico Drainage Basin, North Carolina and Virginia -- Environmental
Setting and Water-Quality Issues. Open-File Report 95-136. U.S. Geological
Survey, Raleigh, NC. 72p.
Harned, D.A., G. McMahon, T.B. Spruill, and M.D. Woodside. 1995.
Water-Quality Assessment of the Albemarle-Pamlico Drainage Basin, North Carolina
and Virginia -- Characterization of Suspended Sediment, Nutrients, and
Pesticides. Open-File Report
95-191. U.S. Geological Survey, Raleigh, NC. 131p.
The Albemarle-Pamlico drainage study unit is one of 60 units of the U.S.
Geological Survey's
National Water-Quality Assessment (NAWQA) Program. The 28,000-square-mile study
unit
includes the large river basins that drain into the Albemarle and Pamlico Sounds
. Land use in the study area is 50% forested, about 30% agricultural, 15%
wetlands, and less than 5%
developed.
Two fact sheets and two reports on the Albemarle-Pamlico NAWQA study unit were
published in 1995. The fact sheets 1) describe the principle water quality
issues in the drainage basin and the design of the study (Spruill et al.) and
2) summarize land use and nutrient concentrations and yields in several streams
in the study area (Woodside and Simerl).
The two reports present existing data pertinent to the quality of the surface
and ground water
resources in the Albemarle-Pamlico drainage area. The Environmental Setting and
Water-Quality Issues report (McMahon and Lloyd) provides general reference
information about the major natural, cultural, and hydrologic factors of the
study unit that influence water quality and describes major water quality issues.
The report also presents the results of an approach for classifying homogeneous
land areas within the study area in terms of environmental-setting
characteristics. This classification can be used to examine the spatial and
temporal correspondence between environmental factors and water quality.
Finally, the report describes methods and assumptions used to compile and
analyze the diverse data used in the report. Information presented in the
report is intended to provide a basis for answering investigative concerns
related to pesticides, nutrients, and suspended sediment.
The Characterization of Suspended Sediment, Nutrients, and Pesticides report
(Harned et al.)
identifies spatial and temporal patterns in ground water and riverine water
quality in the study
unit to 1) provide a foundation for investigation of relations between basin
characteristics and
water quality, 2) identify areas with little existing data, and 3) document
findings for future study cycles of the NAWQA Program in the study unit.
Water-quality data collected from 1950 through 1993 at 66 stations were
examined for the following variables: specific conductance, suspended sediment,
dissolved solids, total fixed solids, total volatile solids, total nitrogen,
total ammonia plus organic nitrogen, total nitrite plus nitrate nitrogen, total
ammonia nitrogen, total phosphorus, and dissolved phosphorus. Pesticide data
for surface water, ground water, and bed sediment were also examined. Results
include trend analyses for the period 1980 through 1990 and estimated sediment
and nutrient loads and trends in loads.
Copies of the reports and fact sheets may be requested (free) from the
Publications Unit, U.S. Geological Survey, 3916 Sunset Ridge Road, Raleigh, NC
27607, Tel: 919-571-4000, Fax: 919-571-4041, email: khedrick@usgs.gov.
Open-File Report 95-136 (Spruill et al.) is accessible on-line at
http://ser1dncrlg.er.usgs.gov/ofr95-164/ofr95-164.html.
USEPA. 1995. Watershed Protection: Clean Lakes Case Study - Watershed and
In-lake Practices Improve Green Valley Lake, Iowa. U.S. Environmental
Protection Agency, Washington, DC. EPA841-F-95-003. 5p.
Two new Clean Lakes case studies have been published by the U.S. Environmental
Protection Agency. The case studies highlight different lake management
techniques that were successfully employed as part of Section 314 Clean Lakes
projects in New Hampshire and Iowa. The management techniques described in the
case studies are 1) phosphorus inactivation and wetland manipulation and 2)
watershed and in-lake practices.
Copies of the case studies (free) may be requested from NCEPI, 11029 Kenwood
Road, Building 5, Cincinnati, OH 45242, Fax: 513-489-8695. The case studies
are (or will soon be) accessible on-line on the U.S. Environmental Protection
Agency's Clean Lakes Program home page at
http://www.epa.gov/OWOW/LAKES
(note: the letters OWOW and LAKES must be capitalized). Also on the home page is
information on the status of lake water quality in the nation, the Clean Lakes
Program, and USEPA lakes publications.
Pastures for Profit describes rotational grazing systems and reasons for
using them. Topics
include plant growth, improving pasture productivity, animal needs, grazing
systems, possible
problems, and practical examples. The report (Pub. A3529) ($3.50 including
postage) is available from Univ. of Wisconsin Extension Publications, 630 West
Mifflin St., Rm 170, Madison, WI 53703-2636, Tel: 608-262-3346.
New York State Department of Environmental Conservation. 1994. Predicting
Pollutant Loading Through the Use of Models: A Supplement to the Watershed
Planning Handbook for the Control of Nonpoint Source Pollution. New York State
Department of Environmental Conservation and New York State Soil and Water C
onservation Committee, Albany, NY. 28p.
The New York State Department of Environmental Conservation has published a
handbook on watershed planning for the control of nonpoint source (NPS)
pollution. The handbook provides step-by-step guidance for preparing watershed-
wide water quality management plans with specific emphasis on the control of n
onpoint sources affecting surface water quality. The publication outlines steps
for 1) identifying water quality problems, 2) establishing water quality goals
and objectives, 3) determining pollution reduction needs, 4) evaluating
alternative NPS control strategies, and 5) preparing and implementing a
watershed management plan.
While the primary focus of the manual is on the control of NPS pollution, it
also provides useful guidance on steps that can be taken to evaluate the
relative importance of point source
discharges in relation to nonpoint sources.
A supplement to the handbook, Predicting Pollutant Loading Through the Use of
Models, is also available.
The two documents may be requested (free) by calling the NYSDEC voice mail
(518-457-3707), sending a fax (518-485-7786), or writing to the Bureau of Water
Quality Management, NYSDEC, 50 Wolf Road, Albany, NY 12233.
This manual focuses on best management practices (BMPs) for wheat production.
Topics include wheat growth, evaluation of BMP economics, environmental issues,
principles of erosion and water quality protection, specific BMPs, and
customized BMP programs.
Copies of the manual may be ordered from the NAWG Foundation, 415 Second St.
N.E., Suite 300, Washington, DC 20002-4993, Tel: 202-547-7800, Fax: 202-546-2638
. The cost per copy is $7.62 (including postage).
The purpose of the newsletter is to provide current technical information on
NPS pollution prevention and control, including federal, state, and local
initiatives and projects; new technologies and approaches; and useful
publications. NWQEP NOTES is also intended to facilitate multi-disciplinary
networking by professionals working in the NPS pollution control field.
NWQEP NOTES is distributed free to over 1,600 water quality managers,
land treatment specialists, and other natural resource professionals in all 50
states and 14 other countries. Publication of the newsletter has been supported
through grants from USDA (1983 - October 1994) and the U.S. Environmental
Protection Agency (USEPA) (November 1994 - present).
To request that your name be added to the NOTES mailing list, contact the
Publications Coordinator, NCSU Water Quality Group, Suite 100, 615 Oberlin Road,
Raleigh, NC 27605-1126, Fax: 919-515-7448, email: wq_puborder@ncsu.edu or use
the publications order sheet included in the hard copy newsletter (see bottom
of the back page).
Purpose
- Provide technical and scientific support for nonpoint source (NPS) watershed
projects with long-term land treatment and monitoring components.
Objectives
- Highlight monitoring of ground water and pasture-grazing practices. Equipment
will be demonstrated.
- Present innovative grazing and nutrient management and ground water
protection practices.
- Evaluate the use of data to target land-treatment in small-scale to
large-scale ecosystems.
- Transfer local knowledge to the regional perspective, highlighting watershed projects in the Chesapeake Bay ecosystem.
- Demonstrate how partnerships can be built among the agricultural community,
program coordination, technical service purveyors, and scientists.
- Discuss program implementation and evaluation challenges faced by the
Chesapeake Bay Program and compare to other regional programs.
Audience
Local, state, and federal personnel involved in implementing and evaluating NPS
watershed projects. Highly recommended for personnel involved in land treatment
and monitoring of Section 319 National Monitoring Program and other watershed
projects.
Structure
Plenary and concurrent presentations and discussions, field trips, and training
sessions focusing on project needs. Informal atmosphere supporting discussion
and interaction. Registration is limited to 150.
Further Information
Patricia Lietman, U.S. Geological Survey, Tel: 717-730-6960, Fax: 717-730-6997,
email: plietman@wrdmail.er.usgs.gov
I welcome your views, findings, information, and suggestions for articles.
Please feel free to
contact me.
Judith A. Gale, Editor
A 30-minute video, We All Live Downstream, recently released by the Oregon State
University Extension Service, examines urban and rural runoff and its impact
on surface and ground water. Although the video was shot primarily in Oregon's
Tualatin River Basin, it is applicable to watersheds throughout the country.
Spruill, T.B., D.A. Harned, and G. McMahon. 1995. The Albemarle-Pamlico Drainage
National Water-Quality Assessment Study: Background and Design. Open-File
Report
95-164. U.S. Geological Survey, Raleigh, NC. 4p.
USEPA. 1995. Watershed Protection: Clean Lakes Case Study - Phosphorus
Inactivation and Wetland Manipulation Improve Kezar Lake, NH. U.S.
Environmental Protection Agency, Washington, DC. EPA841-F-95-002. 7p.
Undersander, D., B. Albert, P. Porter, A. Crossley, and N. Martin. 1994.
Pastures for Profit: A Guide to Rotational Grazing. University of Wisconsin-
Extension and Minnesota Extension Service. 36p.
New York State Department of Environmental Conservation. 1994. Watershed
Planning Handbook for the Control of Nonpoint Source Pollution. New York State
Department of Environmental Conservation and New York State Soil and Water
Conservation Committee, Albany, NY. 30p. plus appendices.
John Hickman, Jeff Jacobsen, and Drew Lyon. 1994. Best Management Practices
for Wheat: A Guide to Profitable and Environmentally Sound Production,
Cooperative Extension System and The National Association of Wheat Growers
Foundation, Washington, DC. 119p.
The National Water Quality Evaluation Project (NWQEP) was initiated in 1980
through a U.S. Department of Agriculture (USDA) grant to the North Carolina
State University (NCSU) Water Quality Group. The purpose of the grant was to
provide technical assistance to 21 federally sponsored experimental agricultural
nonpoint source (NPS) pollution control projects funded through the Rural Clean
Water Program (RCWP). NWQEP NOTES - The NCSU Water Quality Group Newsletter
originated as part of this effort and has been published since 1983.
SPECIAL ANNOUNCEMENT
September 16 - 20, 1996 Harrisburg, PA
EDITOR'S NOTE
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 also available with each issue of the newsletter.
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
email: notes_editor@ncsu.edu
Production of NWQEP NOTES - The NCSU Water Quality Group Newsletter, is
funded
through U.S. Environmental Protection Agency Grant No. X818397.Project Officer: Steven A. Dressing, Nonpoint Source
Pollution Control Program, Office of Water, USEPA (4503F), 499 South Capitol St. SE,
Washington, DC 20460, Tel: 202-260-7110, Fax: 202-260-1977, email:
dressing.steven@epamail.epa.gov, Web Site: http://www.epa.gov/OWOW/NPS