LONG TERM EFFECTS OF A PASSIVE ACID REMEDIATION TREATMENT SYSTEM ON AN ACID-IMPAIRED HEADWATER STREAM IN UNION COUNTY, PENNSYLVANIA

Passive treatment systems such as wetlands and limestone drains have been used to remove acidity and harmful metals from streams impaired by acid mine drainage. Less widely employed, are similar passive treatment systems designed to target negative effects of atmospheric acidic deposition. Data from long-term monitoring of a recently installed combination aerobic limestone basin and anaerobic vertical flow wetland in Union County, Pennsylvania has allowed for the evaluation of remediation effects of one such system on a chronically acidified headwater stream. Depending on flow conditions the Buffalo Creek Acid Remediation System (BCAPTS) effectively raised alkalinity and increased pH values from 0.0 mg/L to 23.0 mg/L and 3.4 to 6.8, respectively. Values of each parameter declined slightly as distance increased downstream of the system. Algae blooms (Cheatophora) initially appeared in the receiving stream immediately below the BCAPTS effluent and correlated with increased phosphate levels, a direct consequence of the nutrients sourced from the system. However, between 5/17/10 and 5/17/12 phosphate concentrations fell from 10.0 mg/L to 0.01 mg/L resulting in an elimination of Cheatophora. Inorganic, monomeric aluminum decreased from 0.30 mg/L upstream to 0.09 mg/L below the treatment system due to increased pH. Further supporting improved biotic conditions, biological EPT (Ephemeroptera, Plecoptera, and Trichoptera) indices show increased aquatic macroinvertebrate diversities over a two year time span and a return of some taxa to previously acidified reaches of Buffalo Creek.