Sanitary Sewer Overflows

Sanitary sewer systems collect and transport domestic, commercial and industrial wastewater, as well as limited amounts of stormwater and infiltrated ground water to treatment facilities for appropriate treatment.

Occasionally, sanitary sewers will spill raw sewage. These types of spills are called sanitary sewer overflows. SSOs can contaminate our waterways, causing serious water-quality problems and back up into homes, causing property damage and threatening public health.

How? Well, raw sewage carries bacteria, viruses, parasitic organisms, intestinal worms, molds and fungi. As a result, it can cause diseases ranging in severity from mild gastroenteritis (causing stomach cramps and diarrhea) to life-threatening ailments such as cholera, dysentery, infections hepatitis and severe gastroenteritis, according to the EPA website.

In the Neuse and Tar-Pamlico watersheds, the main cause of SSOs is predominantly stormwater and/or groundwater overloading a system during tropical weather events, or even a hard rain. Aging sewer infrastructure and new development creating an additional burden on already insufficient infrastructure also contribute to our SSOs. When you have many municipalities, and municipal sewer systems, along the banks of your rivers, the chance that something will go wrong — a pump breaks, a blockage occurs — increases exponentially, as does the chance pollution will pour into our waterways, thousands of gallons at a time.

All that bad stuff entering our rivers, lakes, streams or brackish waters can impact water quality — and not for the better. If we can’t use waterbodies for drinking water, shellfish harvesting, fishing or recreation, that’s a loss: SSOs can close beaches; tourism and waterfront home values may fall; fishing and shellfish harvesting may be restricted or halted.

So how can SSOs be reduced or eliminated?

Investment. According to the EPA, our nation’s sewers are worth a total of more than $1 trillion. Sewer rehabilitation to reduce or eliminate SSOs can be expensive, but the cost must be weighed against the value of the collection system asset and the added costs if this asset is allowed to further deteriorate. Ongoing maintenance and rehabilitation add value to the original investment by maintaining the system’s capacity and extending its life.

What can we do to reduce SSOs? Don’t pour fats, oils or grease down the sink, and don’t flush household items such as baby wipes, facial wipes, sanitary pads and tampons down the toilet—all can contribute to blockages in the system.

Let’s not forget about septic systems, too. If not installed and maintained properly, a septic system can contaminate surface and/or groundwater. If you have a septic system, learn how you can protect local surface water here.