Your Watershed: Sanitary System Overflows

Sanitary Sewer Overflows

Are you aware of their impact?

Sanitary sewer overflows (SSOs)
Sanitary sewer systems collect and transport all of the sewage that flows into them from homes and businesses to permitted wastewater treatment facilities, which are typically Publicly Owned Treatment Works (POTW). However, occasional unintentional discharges of raw sewage from sanitary sewers occur in almost every system. These discharges, called sanitary sewer overflows (SSOs), are defined as any overflow, spill, release, discharge or diversion of untreated or partially treated wastewater from a sanitary sewer system. SSOs often contain high levels of suspended solids, pathogens, toxic pollutants, nutrients, oil and grease.

What causes SSOs?
Discharges of untreated sewage from SSOs often occur due to blockages from build-up of fats, rags, oils, grease (FROG) and other debris, or from structural, mechanical and electrical failures. Infiltration of groundwater or surface water entering the sanitary sewer systems can also contribute to SSOs because these additional flows often exceed the capacity of the collection piping. Aging sewer collection infrastructure potentially increases the occurrence and severity of overflows.

What health risks and environmental impacts do SSOs present?
SSOs can pollute surface and ground waters, threaten public health, adversely affect aquatic life, and impair the recreational use and aesthetic enjoyment of surface waters. Typical consequences of SSOs include closure of beaches and other recreational areas, inundated properties, and polluted rivers and streams.

How to identify an SSO
SSOs can be a very noticeable gushing of water from a manhole or a slow leak that may take time to be noticed. Don’t dismiss unaccounted-for or out of the ordinary wet areas.

Look for:
• Drain backups inside a building
• Wet ground and water leaking around manhole lids
• Leaking water from sewer cleanouts or sewer drains around your home or office
• Unusual foul-smelling wet areas adjacent to sidewalks, external walls or landscaping.

What should you do when you identify an SSO?
Make sure that people are kept away from the area of the overflow. This is especially important for children and pets that may play near the overflow area (streets, public parks or local streams). Report the overflow immediately to appropriate authorities. Remediation can then be undertaken to reduce risk of public exposure to raw sewage by monitoring the impact of the overflow and ensuring proper cleanup.

What to do if you experience a sewer backup
POTWs are committed to building and maintaining a safe, efficient sewer system. Citizens should report any SSOs they see or experience to their POTW or contact their County Sheriff. When a sewer line from your home to the sewer main becomes plugged or causes backups in your home, it’s best to first call a plumber to investigate the cause of the backup. If the plumber finds a problem in the line from your home to the main sewer line in the street, the repair is your responsibility. If the plumber determines the problem is in the sewer main call your POTW.

You are responsible for your lines
You are responsible for a sewage spill caused by a blockage or break in your sewer line. Time is of the essence in dealing with sewage spills. If a sewage overflow occurs due to a problem in your lines, you are required to:
• Control and minimize the spill. Keep spills contained on private property and out of gutters, storm drains, and public waterways by shutting off or not using the water.
• Use sandbags, dirt and/or plastic sheeting to prevent sewage from entering the storm drain system.
• Clear the sewer blockage. Always wear gloves and wash your hands. It is recommended that a plumbing professional be called for clearing blockages and making necessary repairs.
• Always notify your POTW if a sewage spill occurs or if the spill enters the storm drain.

How to start the cleanup process
For professional help in cleaning up after a backup indoors, look in the yellow pages under carpet cleaning and related services. If you begin the cleanup yourself, remember to take basic precautions because bacteria is present in sewage and poses a health hazard.

If You See a Sanitary Sewer Overflow

Notify Your Publicly Owned Treatment Works IMMEDIATELY
This article was authored by Ryan Kirchner of the City of Healdsburg, on behalf of RRWA. RRWA (www.rrwatershed.org) is an association of local public agencies in the Russian River Watershed that have come together to coordinate regional programs for clean water, fisheries restoration, and watershed enhancement.