Sandwich now in compliance with Illinois EPA standards for phosphorus discharge

The city of Sandwich is now in compliance with the Illinois Environmental Protection Agency’s mandate to reduce the amount of phosphorus discharging from the city’s wastewater treatment plant into Harvey Creek.

The city faced a mandate from the IEPA to reduce phosphorus discharge from the plant into Harvey Creek to 1.0 milligrams per liter by Dec. 1. In 2023, it received a $13.9 million state loan that has been used for improvements to its wastewater treatment plant.

The upgrades to the plant improved its ability to remove nutrients, including phosphorus, and improve water quality in Harvey Creek and waters downstream. The project includes a phosphorus-removing chemical feed system, filters, new aerobic biosolids sludge digesters and rehabilitation of the existing digesters.

According to experts, elevated levels of phosphorus can be hazardous to local animal life. Removing phosphorus from water can prevent eutrophication, which causes algae blooms.

“Everything is up and running and we’re within where we need to be now with our numbers for phosphorus,” Sandwich City Administrator Geoff Penman said in updating City Council members about the project during the Dec. 16 City Council meeting.

Sandwich will be required to reduce phosphorous discharge levels to 0.5 milligrams per liter by 2030. The plant was built in 2000 and can treat up to 1.5 million gallons of wastewater a day.

The city received the low-interest loan through the IEPA’s public water supply loan program. The program is funded by state and federal sources.

The 20-year loan has a 1.04% fixed interest rate. The project qualified for an environmental discount to its interest rate for providing nutrient removal.