An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

EPA in Delaware

Protecting the Planet and Pocketbook

Stories of Progress in Achieving Healthy Waters

U.S. EPA Region 3 Water Protection Division

Wilmington, Delaware • April 28, 2016

Two EPA-funded projects at a Wilmington, Delaware water filtration plant are reducing the equivalent of 71 cars worth of greenhouse gases, generating nearly 500,000 kWh in annual energy savings and cutting costs by $876,000 a year.

The improvements at the Porter Street Water Filtration Plant include the installation of rows of solar panels and the placement of a new pump station to reduce costs associated with drawing raw water for processing.

The solar panels, or photovoltaic arrays, provide power through the plant’s electrical distribution network. The green energy cuts greenhouse gases by almost 400 metric tons each year and generates an average of $116,368 in annual savings through reduced electric costs and the sale of solar credits.

The new “low head” pump station allows the plant to draw a full complement of water – not just the top 4 million gallons – from its onsite 36 million gallon raw water reservoir. When it could only skim the top layer, the plant was forced to continually pump water to the reservoir from the Brandywine River during the day – when electric rates are the highest – to keep up with drinking water demand.

The projects demonstrate how a community can make a difference with both offsetting its greenhouse gas emissions and reducing ratepayer costs. In a March 2016 analysis of the two projects, the Kash Srinivasan Group reported that, “the results to date have met the operational and financial performance expectations.”

                                                     Solar Panels       Low HeadPS        Combined

Cost                                                     $5,910,000            $2,990,000            $8,900,000

KWh Saved/Year                                 575,900                 (84,686)                  491,214

GHG Reduced, Metric Tons                  397                       (58.4)                       338.6

Annual Savings                                   $116,368              $759,853                 $876,221

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.