Constructed Wetlands for the Pre-Treatment of Drinking Water Obtained from Coal Mines

Abstract

Greenwood, Arkansas, a city of about 7,700 people in west-central Arkansas, has experienced tremendous growth in population during the past decade. The city has the current capacity to produce 4.55x10 6 L of water daily. De- mand for city water use is expected to exceed 6.82 x10 6 L within the next five years. An additional 2.27x10 6 L per day is needed to augment the current supply. Two abandoned, flooded coal mines located near the city have estimated water storage in excess of 1.97x 10 9 L of water. The water has high concentrations of total dissolved solids (TDS), sulfate, and iron. If a decision is made to use the water, it will require treatment to reduce these constituents to acceptable levels. Designing and constructing a viable wetland for pretreatment of mine water would offer Greenwood an inexpensive, pas- sive method to utilize the water from the coal mines. If the city can use water from the coal mines to augment the present reservoir, the expected savings would exceed twenty million dollars. Integrating this system into the current city park sys- tem and green-space will provide a multi-purpose facility that can be used for recreation, education, and wildlife en- hancement. Terms: Phytoremediation, RAPS System, Iron hydroxide, Anoxic limestone drain, Acid mine drainage.