ABSTRACT

1. A Survey Of The Condition Of Streams In The Primary Region Of Mountaintop Mining/Valley Fill (MTM/VF) Coal Mining J.H. Green (USEPA Region 3), M.E. Passmore (USEPA Region 3), and H.M. Childers (Signal Corporation) ABSTRACT Typical MTM/VF mining operations in the Appalachian coal fields remove overburden and interburden material to facilitate the extraction of coal. Excess spoils are often placed in adjacent valleys containing headwater streams. Although the direct effects of the valley fills on streams are obvious, limited documentation on the indirect, downstream effects of valley fills was available. The biological, physical and chemical condition of streams downstream of a variety of MTM/VF activities was investigated in five watersheds in southern West Virginia, over five seasons. We used a multi-metric benthic index and a regional reference condition to determine the condition of streams in four classes: unmined, mined (some mining activity but no valley fills), filled (valley fills but no residences), and filled/residential (both valley fills and residences). The filled class was impaired relative to the regional reference condition and the local unmined sites, but this class represented a wide range of conditions from poor to very good. The filled/residential class was the most impaired class and the majority of the sites in this class were in poor or fair condition. Further analyses revealed that total dissolved solids strongly influenced the benthic assemblages, while physical habitat parameters were only weakly correlated with benthic condition. OBJECTIVE Characterize and compare conditions in four classes of streams: 1) streams that are not mined (“unmined”). 2) streams in mined areas with valley fills (“filled”). 3) streams in mined areas without valley fills (“mined”). 4) streams in mined areas with both valley fills and residences (“filled/residential”). MONITORING DESIGN AND RATIONALE • Five watersheds across MTR/VF region described by the WVGES (Fedorko & Blake 1998). • Candidate sites (127 total) were selected by WVDEP Inspectors & PEIS Streams Workgroup. • Field reconnaissance and site characterization occurred simultaneously with first sampling event (Spring 1999). • Thirty-seven (37) benthic sampling sites were chosen from original pool of 127 sites. SEASONAL COMPARISON OF BIOLOGICAL METRICS Spring 1999 Summer 1999 Fall 1999 Winter 2000 Spring 2000 WV SCI SAMPLING WITHIN THE MTM/VF REGION IN WV EPT Taxa (Family Level) % Mayflies WV STREAM CONDITION INDEX (WVSCI) PHYSICAL/CHEMICAL CONDITION RESULTS No violation of pH, temperature and dissolved oxygen criteria within the four classes. Elevated conductivity in filled and filled/residential classes. RBP habitat assessments indicated slight impairment in the filled and filled/residential classes. Quantitative substrate size data did not indicate excessive fines in filled class, but results should not be extrapolated to downstream reaches. Correlations indicate that the strongest associations were between biological condition and water quality (conductivity). BIOLOGICAL CONDITION RESULTS Unmined sites were comparable to WVDEP reference conditions and scored in good or very good condition 91% of the time over the course of the study. Mined sites were generally comparable to unmined sites (good or very good 86% of the time). Most mined sites had small amounts of historical mining in their watersheds. Filled sites represented a wide gradient of conditions from very poor to very good. Filled sites scored in the impaired range 66% of the time. Filled/residential class was the most impaired and sites ranged from poor to fair conditions. These sites scored in the impaired range 100% of the time. Diversity and abundance of sensitive mayfly fauna were severely impaired at filled and filled/residential sites. Several unmined sites could not be sampled in summer and fall 1999 due to drought. However, by Spring 2000 all unmined sites could be sampled and were in very good condition. Our data and the scientific literature indicate the ability of invertebrate assemblages to withstand periods of drought. Perennial flows are not required to support a diverse and abundant invertebrate assemblage. • Multi-metric Index. • Metric values were standardized to a common • 100-point scale. WVSCI Thresholds Increasingly different from reference condition & are impaired. Developed using 107 reference samples (Gerritsen et al 2000). EPA R3 GIS TEAM PROJECT SIG 933 HCHILDERS 05/04/01