Wastewater treatment plants often utilize geomembranes to help protect the environment and maximize resources. In San Diego County, the Olivenhain Municipal Water District (OMWD) treats up to 34 million gallons of wastewater each day. The treated water is provided to the community through 45-plus miles of recycled water pipelines. With a seasonal increase in rain, the demand for recycled water drops off and the treated water is stored in a wet weather pond.
This pond has a 13.4 million-gallon capacity and was initially only lined on the bottom. However, it was soon noted that significant leakage was occurring through the unlined side slopes. Compounding the problem, the existing polypropylene liner on the pond bottom was failing.
Given the cost and logistical challenges of replacing the liner, the district needed a long-lasting geomembrane that was much more durable, had superior mechanical strength, and was resistant to weathering. The project specification called for a reinforced product using a blended material with stable ethylene-based polymers in a non-crystalline matrix. The result is a stable, UV and chemically resistant liner.
In 2013, the OMWD selected a 36-mil XR-5® Geomembrane from Seaman Corporation to replace the existing geomembrane, and the district took this opportunity to extend it beyond the access drive near the bottom to the crest of the reservoir. They liked the cream-colored option because it blended into the environment and helped reduce surface temperature, leading to fewer evaporation losses. The project met a number of the district’s long-term needs:
- Secure containment of the treated wastewater prior to reuse.
- Increase storage capacity to 134 MG.
- Minimal maintenance of the containment system.
Completed in 2015, the timing of the project was excellent because the region saw exceptionally large amounts of rain in the winter of 2016-2017. The finished product allows the OMWD to conserve more water more effectively for a longer period while helping to protect the environment.
To learn about how XR® Geomembranes work for storage ponds and more, as well as other geomembrane solutions, contact us today.