 |
Research studies indicate that Americans desire clean water for not only drinking, cooking and bathing, but in our streams as well. The concept of clean water is good and is something we should always strive towards, but it comes at a significant cost. Who pays those costs? The users of the utility systems. In other words, you and I.
 For example, we are currently working hard to remedy a clarifier issue at our wastewater treatment plant (WWTP) that is located on the east side of the city on Rieder Road. The plant has two clarifiers. One clarifier continues to operate effectively while repair is completed on the other unit.
A clarifier removes solids from the already biologically treated water at our plant before the clear water is released into Silver Creek. In this 1,000,000+ gallon tank, the clear water is separated from the solids. The clarifier that is down for repair has had its rotating solids collection arm literally run aground. The finished floor of the tank has separated from the structural floor and is binding against the rotating arm.
The solution is to remove the water, clean the moving parts, remove and replace the floor, repair the arm that has had two inches of metal scraped off its bottom and lost its rubber squeegee, repair the worn pivot bearings that supports the 120 foot arm, rebalance the arm and put the tank back in service prior to winter weather. The cost of this repair will be $117,180.
In addition to clarifier issues, the City received a Notice of Violation (NOV) from Illinois Environmental Protection Agency (IEPA) for exceeding the allowable limit of zinc discharged from our treatment plant. Zinc is monitored to provide an indicator of other heavy metal discharges. Since there are no industrial businesses located in O’Fallon that lead to heavy metal contamination of our wastewater, it has been determined that the zinc levels in our wastewater are coming from the zinc additives that Illinois-American Water Company (IAWC) adds to their water supply prior to our purchase.
The City’s stance on the NOV is that IEPA is permitting IAWC, the bulk water supplier for the O’Fallon, to add zinc concentrations at levels that can not be removed by our plant. As a result, the discharge from the plant cannot meet the standard set for discharge into Silver Creek. The projected cost of removal of the zinc additive to acceptable levels as determined by current IEPA standards is roughly $4,500,000. Design, procurement and construction activities associated with the process will add to that cost.
Our initial attempts to work with IAWC to stop the use of a zinc-based corrosion inhibitor, were encouraging, but IAWC was non-communicative for a long period. As a result, the City sent a letter to IEPA requesting their assistance in directing IAWC to change their corrosion inhibitor program that overloads our WWTP with zinc from their drinking water. Based on our requests, IAWC will now change their corrosion inhibitor process, switching from a zinc compound to phosphoric acid. With this change our zinc discharge should fall below the maximum permissible level, and the violation will be resolved.
| |
