The Bloomington City Council approved an ordinance authorizing a construction agreement between the City of Bloomington and G. A. Rich & Sons, Inc., for Water Treatment Plant improvements at their meeting n Monday night.
Bloomington Public Works Director Kevin Kothe told Cities 92.9, “The project tonight is a chemical feed system for ammonia and chlorine. … The facility is old and outdated. … This project provides upgrades to the facility so that our plant and the people that work in the plant and the people that live around the plant are protected in case there is a leak of chlorine gas.”
The Bloomington City Council approved a Water Infrastructure Master Plan in 2020. The plan included capital projects for improvement, maintenance, and replacement over the next 20 years. The Plan was put together by CDM Smith. It determined that Bloomington is in compliance with current state and federal regulations.
The plan recommended improved ventilation in the main process building. Chlorine gas ventilation was identified as an issue.
According to the plan, “The emergency ventilation systems serving the chlorine application room and chlorine storage room each consist of an outside air louver and an exhaust duct. Each exhaust duct is connected to a dedicated exhaust fan which is remotely located in a separate interior room of the plant.
“The exhaust ducts travel through other spaces of the plant before connecting to their respective fans. The exhaust fan discharge ducts are also routed through interior spaces of the plant before discharging to the outdoors.” the plan says.
Some of the emergency exhaust fans are activated manually by start switches located both outside of the spaces on the building exterior and inside the rooms. The plan recommended that these systems be replaced with a chlorine scrubber system.
Wet Scrubbers remove pollutants by injecting liquid into the gas stream. Chemical Scrubbers inject chemicals into the gas pollutant to strip it out of the waste stream. Chlorine gas is highly toxic. Wet Chlorine Scrubbers may utilize a multi-stage removal approach depending on the initial pollutant loading.
The current ammonia system includes no emergency ventilation system in the event of a leak of the anhydrous ammonia gas. Improvements similar to those being done with the chlorine system will be made to the ammonia system.
The improvements being made are not a result of Bloomington not meeting current standards for operation. However, these items are required in new plants being constructed.
The situation is akin to that of a homeowner who is not required to meet current standards while living in the home but might be required to bring things up to code before obtaining a permit to make improvements to the home or before being allowed to sell the home.
In this matter the City of Bloomington is being prudent and exercising good judgement as good stewards in the interest of safety. Failure to address safety concerns regarding chemicals in water plants can result in serious problems.
In 2019 a chlorine release from a water treatment plant in Birmingham, Alabama sent 50 workers to the hospital. Residents were asked to shelter in place. A combination of treatment chemicals at the plant led to a dangerous release. Sodium hypochlorite (which is essentially bleach) and ferric sulfate were accidentally mixed. These components are commonly used to treat water but are not meant to be mixed.
