The Stringfellow Acid Pits Glen Avon, Riverside County, California. USA

Introduction The watershed area is 270 acres Including the Chino Basin Aquifer, providing a major source of drinking water for 500,000 people. An example of improper disposal of hazardous waste. Over 34 million gallons of chemical waste dumped In use 1956-1972 In 1980, named the most polluted pits in California.

Causes of Contamination Studies showed that the site was situated on impermeable bedrock, approved as a hazardous waste facility. Fractured bedrock and underground Springs Unlined Drainage Channels 34 million gallons of chemical waste were disposed of

Associated Problems Local residents had petitioned to close the site 1979, Stringfellow claimed his company was without assets, and the state of California had to take over responsibility for maintaining the site. It was estimated at the time that a total cleanup would cost $34 million The State agency had to chose a lower cost option – containment.

Effects Health Economic Environmental chemicals were evaporating and polluting the air chemicals leaching out of the dump and contaminating drinking-water supply. nose bleeds to cancer and genetic defects. Economic $15 million has been spent at the site Permanent clean-up option approx. $65 million Environmental More than 34 million gallons of waste Quarry Company disposed industrial waste into an unlined evaporation pond heavy rains dangerous, hazardous materials could flow into nearby water supplies.

Effects The situation continued to deteriorate at the site 1978 rainstorm led to pit flooding During early 1990s, EPA began major remediation efforts Residents won compensation judgements of more than $34 million

1973 to present day Stabilising the Site Closing former waste disposal area Pumping and treating contaminated groundwater Controlling contamination source Cleanup of groundwater in canyon area Cleanup of groundwater in local communities

1973 to present day 1980s: -Site drained and capped -Site has been monitored since 1990s: -installation of extraction wells to reduce contaminant flow 2000s: -new contaminant found (Perchlorate) - Locals supplied with tap water alternative

Future Steps Replacement of PTP New plant will incorporate new technology Learn from our mistakes

Thank you… By: Joshua Gray Lucy Sargeant Ysanne Harding