Research

One function of the DCSWCD is to focus or coordinate technical and educational resources to benefit local land users. Although DCSWCD is not a research organization, from time to time opportunities arise to develop and assemble local information that is not available elsewhere. Such efforts are designed to support the objectives of Delaware County’s Action Plan for watershed management (DCAP), and all major SWCD research projects have relied on available state or federal grants for funding.

Published studies:

L. Day, J. Rall, S. McIntyre and C. Terrance. 2009. Japanese Knotweed Composting Feasibility Study, Delaware County (New York). Ecological Restoration, Vol. 27, Number 4. [In press]

Abstract

This project investigated the possibility of using a municipal solid waste co-composting facility in Delaware County, NY as a means to safely dispose of “Japanese knotweed” (Polygonum cuspidatum). Live portions of mature knotweed stems, leaves, roots and crowns were subjected to conditions within the composting process by using sentinels to contain and allow retrieval of samples from active piles of compost. Samples were subsequently removed from sentinels, planted in pots containing a peat-based growing medium and placed in growth chambers for 30 days. Treatment of three days or more at sustained temperatures >131° F was adequate to kill all samples in the sentinels; moist heat treatment alone for three days between 125° and 131° F seemed equally effective. Results suggest that introducing minor amounts of Japanese knotweed into the present composting process, which currently produces 30,000 tons of finished product annually, may be a preferred disposal option.

L. Day, 2004. Septic Systems as Potential Pollution Sources in the Cannonsville Reservoir Watershed, New York. Journal of Environmental Quality, volume 33, pages 1989–1996.

Abstract

Onsite septic systems require appropriate soil characteristics in order to provide effective wastewater treatment. The objective of this study was to evaluate siting practices and treatment efficacy of onsite septic systems within the Cannonsville Reservoir watershed (115900 ha) in the state of New York. Using digital soil survey data, a database of onsite conditions was developed from over 1100 existing septic system siting records. Soil map units were grouped into four classes based on their suitability to meet common septic system design criteria. A geographic information system was found to be a useful tool for assessment and visual display of septic system and landscape information. Geographic information system analysis indicated that while 80% of soils in the watershed were found to have characteristics that interfere with septic system function, 69% of septic systems installed were of designs suited for soils with no or few restrictive parameters. Since the designs of many septic systems have relied heavily on horizontal distance to streams (mean 130 m) to provide adequate treatment, potential failures would lead to discharge of compounds of environmental concern, such as phosphorus, with public health implications. The results imply that many septic systems functioning in the watershed are in need of design improvements.

[For a copy of the complete paper, contact the author at: larry-day@dcswcd.org]

Unpublished studies:

Monitoring the potential for subsurface phosphorus delivery to streams in the Cannonsville Reservoir watershed. L. Day and S. Pacenka

Abstract for presentation given by L. Day, DCSWCD Soil and Groundwater Specialist, at the 2006 NYC Watershed Conference, Fishkill, NY, September 20, 2006. Steven Pacenka was employed at the Water Resources Institute at Cornell University at the time of this study.

In the Cannonsville Reservoir basin, the prevalent shallow soils overlying fragipan subsoils combined with limited field evidence and modeling calculations suggest the potential for phosphorus to be conveyed by sub-surface drainage to streams, and thence to the reservoir. Calibration of terrestrial non-point source water quality models has yielded coefficients that indicate that up to one third of dissolved phosphorus arriving at the reservoir might be attributed to groundwater. This project evaluated different land uses to determine if groundwater P-loadings to streams can be substantiated. Five study sites were chosen in the Cannonsville basin based on representative land use (forested, agricultural and residential), soil parent material and landscape position (upland or lowland). Groundwater was sampled ~monthly from relatively shallow wells (~1 to 5 meters deep) in unconsolidated deposits across a number of seasons. A long-term forested upland site was used to represent “background” levels of total dissolved phosphorus (TDP), which ranged from about 1 to 15 µg/L. Preliminary results indicate that total dissolved P levels in groundwater at some sites is significantly above these levels. Samples downgradient from actively farmed fields in upland glacial till soils had TDP levels only slightly greater than background, while greater values tended to occur from shallow wells in more porous, gravelly soils in lowland settings.