The City of Elmhurst has instituted a program for removal of "illegal" connections to the sanitary sewer system. Included here are answers to the questions typically asked about the program.
What is a sanitary sewer?
A sanitary sewer is a pipe located in the City Right-of-Way that is designed soley to transport wastewater from sanitary fixtures and floor drains inside your house or place of business to the City's Wastewater Treatment Plant. Sanitary sewers in your neighborhood are owned, operated and maintained by the City of Elmhurst.
What is a storm sewer?
A storm sewer is a pipe located in the City Right-of-Way that is designed to carry storm-related water runoff. Storm sewers are normally much larger than sanitary sewers because they are desgined to carry much larger amounts of flow. Storm sewers are owned, operated and maintained by the City of Elmhurst.
What is an illegal connection?
An illegal connection is a connection that permits extraneous storm-related water (water from sources other than sanitary fixtures and floor drains) to enter the sanitary sewer system. The extraneous storm-related water is water that should be going to the storm sewer or allowed to soak into the ground without entering the sanitary sewer.
What are the different types of illegal connections?
Illegal connections include connections of downspouts, sump pumps and area drains to the house sewer lines. In addition, defective house sewer lines cause extraneous water to enter the sanitary sewers and thus they are also illegal connections.
Where should storm drainage from downspouts, sump pump, and / or other drain appurtenances be directed if it can't be discharged to the sanitary sewer?
Modern subdivision construction standards generally call for water from sump pump, area drains and the like to be diverted to the storm sewers, front or back yards or above ground drainage ditches.
Why is it important for everyone to remove illegal connections?
Removal of illegal connections will significantly reduce the flow of extraneous storm-related water in the sanitary sewer system. This stormwater ends up at the wastewater treatment plant and is treated along with sanitary flow. The cost of treating this clean water could be reduced by reducing the quantity of water from the sanitary sewer.
How can surcharged sanitary sewers cause basement flooding?
A surcharged sewer flows at a level greater than the "normal" level. If the home has sanitary fixtures or floor drains at an elevation below the surcharge level, basement flooding can occur. The sanitary sewers have been designed to transfer sanitary waste only. Extraneous storm water flow added to the normal sanitary flow can exceed the capacity of the sanitary sewer resulting in a situation where the sanitary sewer is "surcharged." Basically, surcharging occurs when the amount of flow trying to get through a pipe exceeds the maximum capacity of the pipe thus building up pressure in the pipe. When pressure builds up it seeks to relieve itself through any means possible, one of which is by backing up private sanitary services and filling basements and crawlspaces. Reducing the extraneous flow will reduce the surcharging and sewer back-ups.
Do illegal connections really contribute large amounts of extraneous water to the sanitary sewer system?
Yes. For example, an eight-inch sanitary sewer can handle domestic waterflow from up to 465 homes; however, it takes only twelve sump pumps operating at full capacity to overload an eight-inch sanitary sewer.
How does the City of Elmhurst identify illegal connections?
The City has completed engineering studies conducted by an independent consultant for the purpose of identifying illegal connections to the sanitary sewer lines. Such studies included smoke and dye testing of the sewers and house lines and house inspections. Also, you are required to call for an inspection when you are selling your home.
If I have an illegal connection what do I do to correct it?
It is suggested that you consult a licensed plumber to determine the most appropriate methods of removing a specific illegal connection.
The following are some possible solutions:
- The sump pipe could be run overland to a ditch or swale that could drain to another location. Also, a long flexible tube that can be moved around the yard to avoid discharge in only one portion of the yard could be used.
- The sump pump can be run underground through a 4" or 6" diameter perforated PVC pipe, with holes at the bottom and backfilled with washed gravel. An overflow tube should be placed at the opposite end to allow the water to escape in the event that the volume of the pipe is exceeded. This pipe tube is located at a convenient area of the yard such as a garden. Another option could be to run it to a drywell.
- Route the sump pump to a City storm sewer via a 6" pipe and tie into the back of an inlet or the crown of the mainline pipe by way of a core hole. No breaking out of the concrete pipe is allowed. If the homeowner is doing the work the City will make the tap. If the homeowner hires a contractor, the contractor is required to do all the work. In both cases, a permit and street deposit (if done by a contractor) will be required with proper inspections made by the Engineering Division.
- Install a 6" diameter PVC storm sewer with drainage inlets to serve as a community backyard drain for a cluster of homes with sump pump connections. The City has an annual program to assist in this type of installation. It is a cost-sharing program with resident participation. Please contact the Elmhurst Department of Public Works for information. Connection to the City storm sewer may by made as outlined above.
Note- Caution must always be taken to prevent freezing in pipes. This could be done by placing a tee where the pipe exits the building. One branch could go underground and the other could be capped off or valved to pump into the yard during the winter. Another option is to have the 2" diameter sump pump tie into the larger 4" or 6" pipe at the house allowing for expansion and overflow. Pipes flowing overland should be kept no farther than 10 feet from the house in winter to avoid icy sidewalks.
I've never had basement flooding due to surcharged sewer. Why should I remove my illegal connections?
You may not have basement flooding due to surcharged sewers. But if your plumbing pumps or drains storm-related water into the sanitary sewer, it may well be the cause of flooding in your neighbor's basement.
Is the requirement to remove illegal connections unique to Elmhurst?
No. In response to U.S. Environmental Protection Agency regulations, local governments have adopted ordinances or codes prohibiting the intrusion of extraneous storm-related water into sanitary sewers. The Metropolitan Water Reclamation District in Cook County has very strict regulations to reduce extraneous flows to sanitary sewers.
Questions?
Call the Elmhurst Public Works Department at (630) 530-3020