ELMHURST – The city began sending out letters Monday to residents who will need to make an appointment for a residential building sewer inspection with RJN Group, an engineering firm hired by Elmhurst to analyze the sanitary sewer.
“It’s coming down in such volume and in such a short amount of time that our system, which was built 100 years ago or more, was not designed to take that kind of rain,” City Manager Jim Grabowski said.
Grabowski gave an overview of current city flood and basement back-up mitigation projects and plans at the League of Women Voters of Elmhurst presentation on Oct. 17 at the Elmhurst Public Library. Interim Director of Public Works Steven Weinstock was also on hand to answer questions.
“Part of the Burke report indicated to us that a lot of stormwater’s getting into the sanitary system,” Grabowski said about Christopher B. Burke Engineering’s findings regarding the city’s stormwater.
He estimated that the current wastewater treatment plant gets about 5 million gallons of sewage on a normal day, but anywhere from 80 to 100 milion gallons of water during a severe storm.
“Houses that have their foundation drains connected into the sanitary systems are a big, big part of that,” Grabowski said.
RJN inspection crews will identify basement storm pumps that may be connected to the sanitary sewer as well as potential outside sources such as downspouts, area drains and driveway drains that may be adding rain water to the sanitary sewer system.
“There was a time when that was standard practice,” said Gary Smith, Elmhurst’s manager of water and wastewater.
Smith explained some homeowners may not even be aware their sump pumps are connected to the sanitary sewer.
The inspections will only look at neighborhoods with a history of sanitary back-ups. The study area is from Madison Street south to Butterfield Road and York Street west to Salt Creek.
“That doesn’t mean that every home in that area is affected,” Smith said.
Only homes that receive a letter from the city will need to make an appointment with RJN, which can be done online either through a link on the city’s website or at rjn.com/buildinginspections. The inspections are expected to take about 10 to 15 minutes while the crews take a look in the basement and determine how the sump pump is connected.
In some cases, an additional inspection will be conducted outside the home. These homeowners will be notified if an outside inspection is needed to check downspouts or other external drains.
In this case, RJN will use a nontoxic, biodegradable dye to study water flow. This allows engineers to study if and how water enters the sanitary sewer.
“We’re collecting information to know what we have out there,” Smith said.
The inspections are expected to be completed in mid-December. Then RJN will submit the findings to the City Council along with recommendations.
An informational meeting on the residential building sewer inspection program will be held at 7 p.m. Tuesday at City Hall. All residents who live in the inspection area are encouraged to attend.
“We want folks to be able to ask all of the questions they have,” Smith said.