Let’s Talk about Sump Pumps

If you use a sump pump in your basement, it is illegal to drain the water into the sanitary sewer. Period.

In 2015, Mayor and Council of the Village of Westport offered a 3-year interest free loan of up to $1000 to assist residents to convert illegal sumps and also amnesty from prosecution.  Not one person has accepted this offer.  It is difficult to understand, in a community as small as ours, why everyone is not part of the solution to reduce unnecessary flows to the waste water treatment plant.  Perhaps some just don’t understand how their continued use of illegal sump pumps contribute in a significant way to the costs we pay for waste water treatment?  Perhaps a few don’t know what to look for in their basement?  I have provided some information that may help everybody to better understand the significance and costs associated to illegal sump pumps.

What are inflow and infiltration?

Inflow and infiltration are terms used to describe the ways that groundwater and storm water enter the sanitary sewer system. Inflow is water that is dumped into the sewer system through improper connections, such as downspouts and groundwater sump pumps. Infiltration is groundwater that enters the sewer system through leaks in the pipe. All of this water is called “clear water” (although it may be dirty) to distinguish it from sanitary sewage.

Why is this water a problem?

Clear water belongs in storm sewers or on the surface of the ground, and not in the sanitary sewers.  When clear water gets into the sanitary sewers, it must be moved and treated like sanitary waste.  This is expensive to treat and limits the capacity of the lagoons for their intended use.

What is a sanitary sewer?

A sanitary sewer is a pipe located in the street or easement that is designed solely to transport wastewater from sanitary fixtures inside your house or place of business.  Sanitary fixtures include toilets, sinks, bathtubs, showers and lavatories.

What is a storm sewer?

A storm sewer is a pipe designed to carry rainwater away.  Storm sewers are normally much larger than sanitary sewers because they are designed to carry much larger amounts of water.  Drainage ditches and swales perform the same function in many neighborhoods.

What is an improper connection to the sanitary sewer system?

An improper connection permits water from sources other than sanitary fixtures and floor drains to enter the sanitary sewer system.  That water should be going to the storm sewer or allowed to soak into the ground without entering the sanitary sewer.   What are different types of improper sanitary sewer connections? Some examples of improper connections include downspouts, groundwater sump pumps, foundation drains, drains from window wells and outdoor basement stairwells and drains from driveways.

Where should the water from downspouts, groundwater sump pumps, and/or other clear water sources be directed?

The Village of Westport’s by-law requires this water to be diverted to storm sewers or above-ground drainage.

Why is it important for everyone to remove improper connections?

Removing improper connections will significantly reduce the flow of clear water to the sanitary sewer system.  This will reduce overloaded sanitary sewers and lessen the amount of water that has to be treated.

Do improper connections really contribute large amounts of clear water to the sanitary sewer system?

Yes, and here’s why: An eight-inch sanitary sewer can handle domestic wastewater flow from up to 200 homes, but only eight sump pumps, operating at full capacity, or six homes with downspouts connected to the sewers, will overload this same eight-inch line. Think of it this way.  Westport has approximately 240 sewer connections. Just 8 sump pumps operating illegally carries the same amount of clean water to the sanitary sewer system as the rest of the village.  We have seen the numbers rise from a normal flow of 300 cu m/day to 1200 and 1300 cu m/day when sump pumps are working.  A recent article in The Review Mirror estimated that 40% of volume processed at the waste water treatment is clear water.  40%!  The math is simple.  In 2014, 73,887 cu m was pumped from the water wells. A total of 117,388 cu m made it to the sewage lagoons.

How much of this is infiltration? (groundwater that enters the sewer system through leaks in the pipe)

At the August Committee of the Whole, Council agreed to move forward and seek proposals from consultants on how best to determine the degree of infiltration.  In the Village of Westport, the sanitary sewer pipes are all plastic and less than 40 years old.  There are five major methods: dye testing, television inspection, smoke testing and flow monitoring and visual inspection when meter reading. Council hopes to have information from the consultants to consider by early November.

If you have any questions, please contact any of the Councillors or me.  By working together, we will improve the efficiency and lower the costs all of us have to pay to operate our waste water system.

Mayor Robin Jones, September 2015

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