Q&A: Avon Lake Basement Backups
Sometimes, rain overloads our city’s storm water system. Many things, including Avon Lake’s soil type, rate of rainfall, and growing amounts of hard surfaces impact the severity of flooded streets, culverts, swales and basements. No one factor is to blame in times of basement-flooding crisis. Noteworthy in times of rain events: Surface flooding (streets, ditches, etc.) is often intentional. When Avon Lake was being built (and still today), developers were required by code to limit flow into the storm sewer through a variety of volume control measures to prevent storm water overflows, limiting the number of basement backups. The most common storm-water controls are detention/retention basins, but control regulators within the streets are also utilized. Without these storm drain restrictions, more storm water basement backups would occur.
There are many ways water gets into basements. Most times, the water is storm water from your home’s foundation drain, which may include water from downspouts and gutters, and can overwhelm sump pumps, especially in case of power loss. However, this Q&A specifically addresses how sanitary (wastewater) basement backups can happen—and why it’s so important for homeowners to join the rest of Avon Lakers who have already taken their home’s storm water out of Avon Lake’s sanitary sewer. Before we get into more specifics, here are some definitions:
Lateral: A pipe underground that connects a house (and delivers its water) to a sewer underneath the street.
Combined sewer: Avon Lake’s original sewer under streets that existed prior to the ‘70s. Mixes storm water and wastewater. Homes connected to it were built with only one lateral.
Storm sewer: The sewer under each street that carries water directly to Lake Erie or a creek/ditch. Most homes in Avon Lake have their own storm lateral that carries storm water (from their foundation drain, gutters and downspouts) to this sewer. Many homes built prior to 1972 do not. The City of Avon Lake is in charge of this sewer and all associated catch basins (drains on the sides of the street) and drains. (Storm drains in backyards are the responsibility of the property owner.)
Sanitary sewer: The sewer under each street in a “separated” neighborhood that carries wastewater (from buildings’ toilets and drains) to Avon Lake Regional Water’s wastewater plant.
Q: Why is Avon Lake Regional Water separating Avon Lake sewers?
A: When sewers came to Avon Lake, they were built according to then-current-day practices—which meant building combined sewers. Homes in these “combined-sewer neighborhoods” collect their storm water and wastewater in a single pipe (a lateral) that carries this storm/sewage mix out to the combined sewer under the street outside.
When built, each combined sewer was equipped with a regulator that diverted the mixed contents directly into Lake Erie when heavy rain filled their combined sewer. However, with the establishment of the Environmental Protection Agency in the early 1970’s, that practice was no longer allowed … and these overflows from the 772 combined-sewer neighborhoods nationwide had to be curtailed. Thus, Avon Lake (and other cities) began mandating separated sewers for all new homes built, and promised to modify all combined sewers to reduce lake-dumping of raw sewage.
Q: What makes water back up into basements?
A: Most basement backups are caused by storm water coming into a home’s foundation drain and overwhelming the sump pump, or a plugged foundation drain. Though Avon Lake Regional Water has no control or influence over Avon Lake’s storm water sewer system, storm water can negatively impact our sanitary sewer system, too, causing sanitary basement backups. (Keep reading for more on this.)
Q: Is there a relationship between basement backups and combined sewers?A: Yes. Though storm water can enter the sanitary sewer from a number of places, one of the primary sources is through homes which used to be on combined sewers, but whose residents did not remove their home’s foundation drain water from the sanitary sewer at the time of separation.
During previous decades-worth of sewer separations around town, we’d hoped to save homeowners the expense of building a new lateral for their home’s foundation drain water. Though we recommended they remove their foundation drain water from the sanitary sewer, we didn’t require it. The storms of 2011 (and resulting basement backups) showed that policy wasn’t sufficient. Now all Avon Lake homes must remove their storm water from our sanitary sewer.
To give homeowners who need to separate their home’s water more time to save money to pay for their project (it’s a multi-thousand-dollar undertaking), we allowed a five-year grace period, rather than the three-year period we’d originally proposed. This delay helps folks afford their project. However, in the interim, strong storms wreak havoc on basements that are similar in depth to nearby sanitary sewers still receiving large amounts of water from these formerly combined homes whose residents have not yet removed their home’s storm water from the sanitary sewer.
Q: Avon Lake has seen a lot of new neighborhoods popping up in the last 20 years. Does that cause sanitary sewer backups in basements?
A: No. From a sanitary sewer perspective, while wastewater volume does rise with population, no matter how many homes are built in Avon Lake, sanitary sewers under the streets will never get full enough with wastewater alone to back up into basements. Overflows in the sanitary sewer happen with the influx of storm water that accompanies heavy rain events, and new homes are built with separate storm laterals/sewers, so none of their storm water ever gets into the sanitary system.
Q: What are you doing to help?
A: Separating sewers in Avon Lake will help satisfy the Ohio EPA, but it will also reduce basement backups. However, until all Avon Lakers remove their homes’ storm water from Avon Lake’s sanitary sewers, some homes, especially those close to Lake Road, or, with deep basements, are still at risk of sanitary-sewer-surcharge basement backups.
To help further decrease this risk while we wait for homeowners to remove that water from the system, Avon Lake Regional Water has been building temporary flow-relief valves (similar to what combined sewers have) near these formerly combined neighborhoods to re-route storm-water-swollen sanitary sewers into Lake Erie. While these new valves went unused since their 2012 construction, they were used in September 2014 and June 2015—and while they prevented flooding then, they weren’t enough to prevent a few sanitary sewer basement backups in June 2015. So we’re building another. As always, we’ll continue working to mitigate storm-water impact on our sanitary sewers while we allow Avon Lakers to complete their own separation projects.