The Pinewood Site operated as a claystone mine from 1972 to 1978. In 1978, it began operating as a landfill. After November 1980, it operated as a hazardous waste site when South Carolina's hazardous waste regulations became effective.
The Pinewood Site received hazardous and nonhazardous waste until 2000 when site closure began. All landfill cells have since been closed and capped. The site will remain in post-closure care for at least 100 years.
What is Leachate?
- Water that collects contaminants as it drips through waste in a landfill.
- Typically contains 90% water and 10% contaminants.
- Includes solid particles such as sand.
- Leachate is not contaminated groundwater.
Leachate must be pumped out of the landfill to prevent overfill. A Leachate Collection System collects the leachate and pumps it out.
Current Leachate Management
Leachate generated by the landfill requires collection, storage and disposal. Leachate is currently collected, filtered and stored in an area on-site prior to being shipped by truck to out-of-state treatment facilities for disposal. Alternate disposal options must now be considered due to changes in the makeup of the leachate over time and the limited availability of out-of-state treatment and disposal facilities.
Proposed Leachate Management
Alternate disposal options considered included off-site disposal and on-site treatment. After evaluating the technical and economical issues of each option, DHEC believes that the best option will be to treat the leachate on-site using an evaporator (like boiling water) and trucking the residual solids out-of-state for disposal.
This treatment and disposal option will require changes in the current hazardous waste permit and a new air permit for the site. DHEC will be accepting comments on both permits once they are drafted.
Groundwater monitoring is conducted on a routine basis around the closed landfill cells to determine groundwater quality. No releases from the landfill cells have been detected in the groundwater.
Stormwater is collected and discharged in accordance with Pinewood's current National Pollutant Discharge Elimination System (NPDES) permit.
Completed Improvement Projects
Beginning in 2009, the Pinewood Site underwent several improvement projects, including:
- Stormwater management updates.
- Power system and electrical upgrades.
- Updated computer control system for monitoring leachate.
- Leachate storage upgrades.