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

2. 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
In 1980, named the most polluted pits in California.

3. 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

4. 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.

5. 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.

6. 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

7. 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

8. 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

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

10. Thank you…
By:
Joshua Gray
Lucy Sargeant
Ysanne Harding