Savannah River Basin REMAP:
A Demonstration of the Usefulness
of Probability Sampling for the
Purpose of Estimating Ecological Condition
in State Monitoring Programs
EPA 904-R-99-002 / April 1999
ECOLOGICAL ASSESSMENT BRANCH
US-EPA, Region 4, SESD, Athens, Georgia
The Environmental Protection Agencys Environmental Monitoring and Assessment Program (EMAP) is an outcome of EPAs National Eutrophication and Acid Lake Monitoring Programs of the 1980s. EMAP is a statistical sampling program that has adopted a uniform approach for national and regional monitoring assessments across ecosystem types. EMAP uses a serially alternative probability-based sampling design that systematically allocates sampling effort over space and time to ensure adequate coverage followed with randomization to ensure unbiased estimates of status throughout the life of a project. The design does not rely on assumptions of population distribution, but describes the underlying structure of the population of interest. The approach is flexible and applicable to all landscape media. It has the ability to increase or reduce sampling density down to the ecoregion level, respond quickly to environmental problems, maintain representative coverage of environmental resources, and provide for sampling of fewer sites in an area but over rotating cycles. Through this project, an interval-overlap technique is presented that minimizes the loss of monitoring data when the EMAP approach is incorporated into a fixed station (judgement) monitoring program. The technique uses a back-prediction method with a bias-corrective factor to best fit the two types of monitoring derived data.
In cooperation with EMAPs desire to transfer this monitoring approach to the EPA regions and states, Region 4 established the Regional Environmental Monitoring and Assessment Program (REMAP). Region 4 teamed with scientists and managers in EPAs Office of Research and Development and the states of Georgia and South Carolina to conduct a demonstration of the new monitoring approach, answer questions about probability sampling and analysis, and address the concerns about the ecological condition of streams and large lake tributary embayments in the Savannah River Basin.
From a basin perspective, the tributary embayments with regard to trophic condition are in good condition. At worst, only about 5% of the acreage exhibited less than desirable conditions. There appeared to be a general decline southward with respect to stream EPT Index, dissolved oxygen, and conductivity. Average stream temperatures increased southward. Water quality violations were noted for dissolved oxygen and pH. A dissolved oxygen violation was noted on an unnamed tributary to Cliatt Creek in Columbia County, Georgia. Likewise about 8% of the stream miles were less than both states pH standard of 6.0 and 2% of the miles were greater than the allowable South Carolina standard. An examination of basin-wide stream conditions over a two-year period indicated that up to 52% of the stream miles were in poor ecological condition.
Because of a sufficient number of reference and sampling stations in the Lower Piedmont Ecoregion, EPA scientists focused on that scale in assessing stream condition over a four-year period. Consolidating information from an EPT Index, Fish Index, and Habitat Score, scientists developed a Lower Piedmont Ecological Index (LPEI). The LPEI showed that 69% of the Ecoregions stream miles are in fair to poor ecological condition. Most of this adverse impact is attributed to habitat degradation in the form of excessive sedimentation. One area of the landscape along the I85 corridor showed an unusually high number of poor stream sites and it is the conclusion of the scientists that this area is in need of further study.
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|Savannah River Basin REMAP|
|67 pages||624 KiloBytes||Main Report|
Listed Below are Individual Appendices of this Report
|3 pages||6 KiloBytes||
|4 pages||10 KiloBytes||
|44 pages||118 KiloBytes||
Fish Protocol & Stream Data
|15 pages||30 KiloBytes||
Savannah River Basin landscape Analysis (Text)
|15 pages||45 KiloBytes||
Savannah River Basin landscape Analysis (Tables)
|25 pages||9799 KiloBytes||
Savannah River Basin landscape Analysis (Figures)
|116 pages||497 KiloBytes||
Sampling Design Issues
|6 pages||11 KiloBytes||
Peer Review Comments and the Response