Superfund record of decision: Highlands Acid Pit Site, Texas.

The Highlands Acid Pit site is located 16 miles east of Houston on a 6-acre peninsula in Harris County, Texas. The site is bordered on the west and the south by the San Jacinto River, on the north by a wooded area, and on the east by a sand pit. The site lies within the 10-year flood plain and has subsided 2.4 feet since 1964. An unknown quantity of industrial waste sludge was disposed of at the site in the 1950's. The sludge is believed to be spent sulfuric wastes from a refinery process. Waste materials at the site exibit a low pH and elevated concentrations of organics and heavy metals. Extensive excavation with off-site disposal was selected as the cost-effective remedial action for this site. The selected remedy includes: disposal to RCRA facility, backfilling te excavated area, constructing a temporary site perimeter fence and performing ground water monitoring adn site maintenance for 30 years. Alternate Concentration Limits (ACL's) will be developed for this site. The capital cost for the selected alternative is estimated at $2,407,000 with annual monitoring and maintenance costs at $14,000.