Thanks to all who answered our survey or submitted comments on the options for reducing sewer overflows to the Illinois River. Although the public comment period has expired, your questions and ideas are always welcome. Click on the "Contact Us" link at left to send an email to a member of the project team.

If you were unable to attend the public meetings, a summary of public comments received can be found below. You will also find the meeting handouts, meeting presentation, and a list of frequently asked questions and answers.

You will need Acrobat Reader to view the meeting materials. You can download it for free at www.adobe.com.

Q. What is the main difference between the three options being considered? Do they provide equal treatment?

A. Yes, the three options would provide equivalent treatment to sewer overflows. All options would reduce overflows from the current 28 or more per year to 2-6 treated overflows in a typical year. Overflows that do occur would be screened for solids and floatable materials and disinfected. We would also reduce the number of overflow locations from 16 to four or fewer.

The main difference among the options is the location where treated overflows would occur most often. In the typical year Option 1 would move treated overflows to the I-74 bridge and downstream. Option 2 would move overflows further downstream – to the Bob Michel Bridge. Option 3 would move overflows to the GPSD treatment plant.

Q.  Will Option 2 completely eliminate all overflows upstream of the Bob Michel bridge? Will Option 3 completely eliminate all overflows upstream of the GPSD treatment plant?

A. No. Options 2 and 3 will eliminate overflows in those areas only during years with typical rainfall or less.  Some years will be wetter than the typical year, and large storms will cause overflows in upstream areas. The city is planning to screen and disinfect the overflows that remain, but even that may not be possible during very large storms.

Q. What do you mean by a “year with typical rainfall?”

A. The project team looked at 58 years of rainfall records in Peoria to determine our average rainfall. The “typical year” is the year that most closely resembles Peoria’s average historical precipitation—in terms of rainfall volume, number of rainfall events, and extreme storm intensities and volumes. Over a long time period, we would expect that half of the years would be wetter than normal and half would be drier than normal. We use the typical year to predict how frequently a storage tank or sewer would overflow on average, recognizing that some years will see above average performance and some years will see below average results.

Q. Why not build more storage tanks, instead of just four or fewer?

A. The project team found that using four or fewer storage tanks would be the most economical approach, both from a construction and operation/maintenance standpoint.

Q. Why were these three options chosen as the most viable options?

A. The City continues to look at various options for controlling overflows. It’s important to remember that state and federal agencies may ask us to look at additional options, as well. These three options are being presented to the public because they meet state requirements to capture the first flush of rainwater entering the sewer system, but differ in where overflows would occur most frequently. The options present preliminary ideas that are still being refined by project engineers.  The City wanted to gather public input on the future location of treated overflows. The City must determine whether it is important to the public to move most treated overflows downstream, even though it will cost much more.

Q.  Why not separate the sewers?

A. The project team looked at sewer separation as an option, but determined that it was too costly at $500 million to $600 million. Sewer separation is also very disruptive and would leave urban stormwater untreated. Stormwater carries bacteria and other pollutants that contribute to problems in the Illinois River. Under the City’s federal stormwater permit, new storm sewers must include best management practices to reduce pollutants.  The proposed sewer overflow control options can capture and treat this stormwater more cost-effectively than separating the sewers and sending stormwater to the river. The City has identified two areas where separate storm sewers discharge to the combined sewer system.  We expect that the final plan will include disconnecting these areas from the combined sewers at a relatively low cost.

Q. How long will it take to complete construction of these projects?

A. We don’t know yet. The schedule will be negotiated with the Illinois Environmental Protection Agency and the U.S. Environmental Protection Agency. Many communities have been given 20 years to complete the required projects.

 Q. Upon what is the state’s bacteria standard based? Is it based on health studies or effects of bacteria on people’s health?

A. Federal water quality guidelines for pathogen criteria were first proposed in 1968, based on studies done in the 1940s and 1950s at bathing beaches located on Lake Michigan, the Ohio River, and on Long Island Sound. In 1976, the U.S. Environmental Protection Agency recommended a fecal coliform bacteria standard of 200 colony forming units (CFUs) per 100 millilters, expressed as a geometric mean, or average, of several samples.  Additional studies were conducted from 1972 to 1980, leading to 1986 recommendations from U.S. EPA that states use enterococci or E. coli as fresh water indicators of the presence of human waste. However, current bacteria tests do not distinguish between human and animal waste, and take 24 hours to provide results. Illinois EPA continues to use fecal coliform in its standards, as do several other states. U.S. EPA is researching tests that could be more specific to human pathogens. 

Q. Should we bring back the private cisterns that were once used to hold rainwater in Peoria?

A. Cisterns were sometimes used in homes years ago as a source of water for washing, cooking and drinking. However, health concerns and environmental regulations required the City to shut down cisterns and bring in a healthier water supply for residents. Today, we recommend rain barrels as a better alternative to cisterns for capturing rainwater for use in watering your lawn and garden. Water from cisterns or rain barrels is not recommended for drinking or cooking.

Q. Did the project team consider wetlands along the riverfront to filter stormwater?

A. Wetlands can be used to filter and treat stormwater runoff, but if we tried to control all stormwater that falls over the combined sewer service area, more land would be required than we have available along the Peoria Riverfront. The City will be considering wetlands, rain gardens and other green solutions to capture or slow rainfall runoff and provide stormwater treatment in smaller areas where they make sense.

Q. Are the deadlines the same for all communities or will we get contaminated flow from other cities that could negate our dollars spent?

A. Each community will negotiate its own schedule for meeting Clean Water Act requirements with state and federal agencies. Most communities receive 15, 20 or more years to complete these types of projects. However, all combined sewer communities should be required to achieve compliance eventually. Implementation of long term control plans in other communities should reduce the effects of upstream CSO discharges on Peoria’s water quality. It’s also important to remember that other sources of bacteria will remain even after combined sewer issues have been addressed, such as agricultural runoff and stormwater runoff from Peoria and upstream areas. Illinois EPA will be responsible for addressing these additional sources of bacteria outside of the City’s control.

Q. I’m not sure of the best choice due to operating and maintenance costs. What is the best option for consideration of long-term maintenance costs?

A. Because of our tight schedule, we needed to seek public input on the options and their estimated capital costs before we had operation and maintenance costs available. We expect operating costs to increase somewhat with each additional storage facility we build. Each storage unit will require electricity, cleaning and regular maintenance by City staff or GPSD. For this reason, Option 1 consolidates overflow locations where feasible and most economical, resulting in four storage/treatment units. Options 2 and 3 further consolidate overflows into fewer storage units in order to relocate them downstream as much as possible. This relocation comes at a significant additional capital cost. We expect to have operational costs at a later date and will share these with the Clean River Committee and the community before a final decision is made on the best option.

Q. What are costs to increase capacity of existing main treatment facility, plus green, plus separation?

A. The project team is continuing to evaluate the most effective methods for controlling the sewer overflow problem, including green infrastructure and sewer separation where they are cost-effective. The final option is expected to include a mixture of all three: additional storage/treatment capacity, green infrastructure and sewer separation.

Q. What is porous pavement?

A. Porous pavement is a special type of pavement that allows rain and snowmelt to pass through it, thereby reducing stormwater runoff. In addition, porous pavement can filter some pollutants from the runoff. Porous pavement options include porous asphalt and pervious concrete, which are made with coarser materials that leave small voids for water to drain through. Other options include grass pavers, which have concrete interlocking blocks or synthetic grid systems with open areas designed to allow grass to grow. Porous pavement may substitute for conventional pavement on parking areas or areas with light traffic.

Q. How would chlorine disinfection work?

A. During most storms, excess wet weather flow in the sewer system will be sent to the storage facilities for later treatment, or conveyed directly to the GPSD wastewater facility for treatment. In a typical year, two to six times storms will be large enough to completely fill the storage tanks and interceptor. Under these conditions, excess flow from the combined sewers will be directed to a screening facility to remove floating debris and larger solids and provide disinfection to kill potentially harmful bacteria.

Q. How much chlorine will be needed at each area?

A. The amount of chlorine needed will be determined later during final design.

Q. How are you addressing the health and safety concerns of have an industrial chlorine-based process in a busy public space?

A. For planning purposes, we are assuming that chlorine will provide the most cost-effective disinfection method. Chlorine can be applied in gaseous form from cylinders or as liquid bleach. For safety reasons, the plan assumes that liquid bleach would be used. Liquid bleach can safely be stored at secure remote locations, and would not be considered a risk for surrounding residents. We will re-examine other disinfection methods, such as ultraviolet radiation and ozonation, during design of these facilities in the future.   No matter what disinfection method we use, facilities will be designed and constructed in accordance with applicable codes and regulations.

Q. While I agree that litter in the river is unsightly and highly undesirable, is there a direct tie to the fecal coliform levels? Does the litter in any measurable way contribute to the overall volume of sewer/stormwater in the system? How much are you thinking about spending for litter education?

A. U.S. EPA policy requires that floatables, including trash and litter, be controlled as part of the overall control of combined sewer overflows.   Litter can affect the volume of overflows by interfering with control devices used within the sewer system to manage wet-weather flow and by contributing to blockages in the sewer system. Litter education programs can be effective in reducing litter that might be discharged to the Illinois River and improving sewer system operation. We don’t know yet how much we would spend on litter education. This needs to be considered within the overall cost of the overflow control program.