The City of Bloomington has an NPDES Permit to operate several CSO's (Combined Sewer Overflows). A copy of the most recent NPDES permit to discharge into waters of the state is available here for public viewing. Please check this website periodically for updates regarding this important matter.

Combined sewers have both sanitary and storm water running through them. Under federal mandate, the City spends millions to separate the sewers. Here are reports on the effort to manage and eliminate Combined Sewer Overflow.

• Combined Sewer Overflow Reporting Procedures
• BNWD Long-Term CSO Control Plan, April 2003
• BNWD Long-Term CSO Control Plan, Addendum 1
• CSO Pollution Prevention Plan
• CSO Operational Plan

Please contact the Public Works Department at stormwater@cityblm.org to make further inquiries regarding this matter.

The City of Bloomington, in conjunction with the Town of Normal and the Bloomington and Normal Water Reclamation District (BNWRD), own and maintain three types of sewers within the Bloomington - Normal area. These include storm sewers, sanitary sewers and combined sewer systems. Many people are aware of the purpose of the storm and sanitary sewer systems, but are not familiar with combined sewer systems.

A combined sewer system is a system in which both the runoff generated by melting snow or rains AND sanitary waste water flow through the same pipe. This system generally carries sanitary waste during periods of dry weather, but carries both sanitary waste and the runoff from melting snow or rainwater as these weather situations occur. The combined sewer system is designed to handle most typical rain and snow events, but becomes overloaded during periods of heavy rainfall or sudden downpours. It is during these heavy rains and sudden downpours when the combined sewer overflows (CSOs) operate. A combined sewer overflow is an event which occurs when a combined sewer exceeds its capacity and begins to discharge excess water into a nearby receiving water. The combined sewers within the City of Bloomington are located north of Veteran’s Parkway and West of Mercer Avenue. However, some of the storm and sanitary sewers outside of this area flow into main trunk sewers within this area, thus contributing to the combined sewer system. The City of Bloomington currently monitors 4 combined sewer overflow locations on a daily basis.

Combined sewers are not a new concept. Municipalities nationwide began using combined sewers in the early 1800’s. They were built until the 1960’s when the United States Environmental Protection Agency (U.S. EPA) began requiring new sewer installations to be separated, i.e., storm water would only enter the storm sewer system and sanitary waste would only enter the sanitary sewer system.

The passage of the Clean Water Act in 1972 led to the U. S. EPA prohibiting CSOs and required municipalities to eliminate them unless an economic hardship could be proven by said municipality. The BNWRD facility requested a waiver of this requirement based upon economic hardship in 1983 as it was estimated the cost to comply with this mandate would be roughly $40 million. BNWRD began implementing phased changes to the West Oakland Avenue plant as part of the agreement with the U.S. EPA.

The U. S. EPA implemented 9 minimum control measures for Combined Sewer Overflows in 1996. These measures are as follows:

1. Proper operation and regular maintenance programs for the sewer system and CSO outfalls;
2. Maximum use of the collection system for storage;
3. Review and modification of pretreatment requirements to ensure that CSO impacts are minimized;
4. Maximization of flow to the Publicly Owned Treatment Works (POTW) for treatment;
5. Elimination of CSOs during dry weather;
6. Control of solid and floatable materials in CSOs;
7. Pollution prevention programs to reduce contaminants in CSOs;
8. Public notification to ensure that the public receives adequate notification of CSO occurrences and impacts;
9. Monitoring to effectively characterize CSO impacts and the efficacy of CSO controls.

The U. S. EPA also required entities that have CSOs to implement a Long Term CSO Control Plan. The BNWRD staff created Illinois’ first Long Term CSO Control Plan to be approved by the U. S. EPA.

The funding of sewer system maintenance and improvements is through charges on the water bill. There are separate sewer charges for the City Sewer System which conveys the sewage and the BNWRD treatment of the sewage. Increases in the rates for the sewer charges are established independently. The City utilizes a sewer rate study to determine what the rates should be.

Smoke testing involves blowing smoke through the sanitary sewers to locate and document potential areas of inflow and infiltration of stormwater in the sanitary sewer system. This is part of an effort to help the City remove unwanted wet weather flows in the sewer system, a required step in order to meet our obligations with the Bloomington-Normal Water Reclamation District (BNWRD). Removing inflow sources is key to reducing flow rates to the Kickapoo Wastewater Treatment Plant, which is currently operating at capacity when significant rainfall occurs.

During the testing procedure, you may see smoke coming from vent stacks on buildings, holes in the ground, or downspouts. The smoke varies in color from white to gray depending on density and lighting. It is NON-TOXIC, NON-STAINING, HAS NO ODOR, AND CREATES NO FIRE HAZARD. The smoke leaves no residuals and will not harm you or the health of your pets or plants. The attached materials include information on the smoke system used for this field testing, including a Material Safety Data Sheet (MSDS) for the smoke.

The smoke should not enter your home or business unless the existing plumbing has a deficiency. If you have any seldom-used drains, please pour water in the drain to fill the trap prior to the test, as smoke could enter your home through a drain that is dry. The testing should not affect your home or your sanitary sewer service. You do not need to be present during the testing and workers will not be inside your home. Smoke could enter your home through drains if the trap is not filled, so be sure to POUR WATER DOWN ALL THE DRAINS IN YOUR HOME, ESPECIALLY SELDOM-USED DRAINS AND FLOOR DRAINS IN YOUR BASEMENT, SLAB FLOORS, AND GARAGES. If you have a smoke alarm that automatically calls the fire department, pouring water in your drains is particularly important to ensure that the fire department is not called unnecessarily.

Smoke testing is conducted by a team of consultants and contractors hired by the City. Crews will be in marked vehicles and have proper identification. Anticipated working hours are from 8 am to 5 pm on weekdays with the potential for work on Saturdays. Notifications are sent to the Bloomington Police and Fire Departments and are posted on the City of Bloomington website before work is scheduled to begin.

If there is an immediate problem or concern during the smoke testing, contact one of the field crew members who are conducting the testing in your area. They will be happy to respond to your inquiries. If you have further additional concerns, you can contact the City of Bloomington Public Works Department at (309) 434-2225.

Smoke testing of sanitary sewer collection systems was initiated in 1961 at McPherson, Kansas. Excessive infiltration was a problem, and the most practical method developed was a visual test utilizing smoke that would meet the following criteria: relatively harmless; free from oily or colored stains; allow sewer personnel to operate without the danger of fire or explosion. Superior Smoke satisfies these requirements and has proven itself by over 30 years of successful field experience.

Smoke testing of sanitary sewer collection systems is endorsed by EPA in all regions, and included as an integral part of contracted inflow/infiltration studies. Zinc chloride type smoke, preferred by the Environmental Protection Agency, is manufactured by the Superior Signal Company, and has been the choice of sewer service contractors and municipalities for over 30 years.

Superior® Smoke has the exclusive properties of leaving no visible residue and containing no explosive materials. Approximately 50% of the visible portion is atmospheric moisture. Small amounts of smoke mixed with large volumes of air, utilized in the Smoke Testing Technique for sanitary sewer collection systems, can enter dwellings through the same faults in house plumbing systems that provide egress of lethal and/or explosive sewer gases. The tests are performed under infinite volume conditions due to the characteristics of the sewer system. The concentration of smoke at a specific point would be influenced by the infinite volume of the system, size of fault, velocity of air flow, duration of test, and position of the blower in relation to the fault. Considering the amount of air/smoke mixture induced into the test segment, size of faults, duration of tests (minutes), infinite volume of the system due to roof vents, probably less than 1% of the smoke would be found at any one leak.

Superior® Smoke is not a true smoke, but contains a large percentage of atmospheric moisture that provides high visual obscurity at low concentrations. The mist formation is seeded by zinc chloride and some other products of combustion such as free carbon. The toxicity of the materials must be represented relative to the application and, in this case, brief exposure time.

Notices sent out within 24 hours of smoke tests should advise the nature of the tests and request individuals to notify the administrators of the program concerning anticipated personal problems. While giving advance notices, discrete neighborhood inquiries can identify persons suffering from lung ailments such as emphysema, who should never be exposed to any smoke. The necessary arrangements to cooperate in any manner as not to jeopardize their condition can be completed at this time.

Authorities in the Occupational and Environmental Health Departments of several universities, including Dr. James Sterner, Professor of Occupational Health, College of Medicine, University of California, and Dr. Jack E. Peterson, Associate Professor of Civil Engineering of Marquette, Professor of Occupational and Environmental Medicine, University of Illinois, Ph.D. Industrial Health, Certified Industrial Hygienist, have extended opinions in support of Superior Smoke. Based on the reported data and theory, these people believe Superior™ type smoke to be the best available source of smoke.

Superior® Smoke satisfies your smoke test requirements; economical, convenient, effective. With a T.O.P. of 2100, it is ten times more efficient than crude oil. Millions of feet of sewer line have been smoke tested, and less than 1% of the houses tested have had smoke enter them. Through this type of testing program, overloading of residential sewer lines causing backups of sewerage into homes and discharges of improperly treated sewage from overloaded treatment plants can be minimized.

Superior Smoke MSDS

Sewer lining is a process of rehabilitating a sewer. Bloomington uses it, because it is proven effective and efficient. It is affordable, saving millions of dollars compared to a more time consuming process of excavating, removing old sewer, and laying new pipe.

Think of a large tube sock. The sock, or the liner, is pushed through the sewer pipe with steam, water, or air. The liner clings to the side of the pipe. It then cures and hardens, forming a fiberglass-like shell coating the old sewer pipe. The liner becomes a pipe inside a pipe. The City expects a liner to last several decades. It is the primary method of sewer rehabilitation envisioned in the Bloomington sewer master plan, which was created by a team of specialists and adopted by the City Council on September 14, 2015.

Sewer lining is overseen by the Engineering Division of the Public Works Department. The City obtains competitive bids from private contractors to do the actual construction annually.

During liner installation, you will lose service, but only for a portion of the day, in nearly every case. When the liner goes in, it covers up all the services that connect the sewer main to customers. For a time, your building is essentially plugged at the sewer main. PLEASE DO NOT shower or do laundry during the installation and refrain from all use of toilets and faucets. The lining crew must wait for the liner to cure (time various based on size of the pipe). The crew will then cut open the services, either by hand or by mechanical means. When your area is under liner construction, the City and its contractor circulate notices. Those notices will specify the times in which a property will be out of service, and during that time you should not use any water.

On occasion, air pressure during lining can push water out of a toilet. It is recommended to use the following preventative measure: Drape a towel over the rim of the toilets prior to the work beginning. Close the toilet seat and lid over the towel.

Sometimes an odor enters property during the lining process. Customers sometimes describe it as smelling like glue. The cause of the odor is a widely used resin. However, the actual cause of the odor entering the building may be a private plumbing issue. In cases in which odor enters the building, the odor usually enters through a floor drain, usually located in the basement, but vapors also can enter through bathroom plumbing. Prior to the lining work, pour water into the floor drains and run a small amount of water through all sinks. Cover the floor drains.

If your building smells during or after the lining work, ventilate the building and call Bloomington Public Works at (309) 434-2225. The presence of the odor from the sewer may be a sign of a plumbing problem in the building. In some cases, a licensed plumber is needed to inspect, diagnose, and correct a sewer-odor problem. Public Works can advise to an extent, but the Department doesn’t employ plumbers and, by policy, does not recommend plumbing companies. Be mindful that if resin vapors are entering your building during lining, you can assume that sewer vapors are entering at other times. Plumbing should prevent vapors from traveling from a sewer into a building at all times. Additives may be used to change the odor, making it less unpleasant. One additive may make the vapors smell like grape. However, regardless of the smell, the concern remains. Please contact Public Works.