Three LaSalle Facilities Discharge into Little Vermilion River Under Loosely Enforced IEPA Permits 

By Jamie Hicks

LASALLE, Ill. — Public environmental records show three major facilities in LaSalle are permitted to discharge wastewater into the Little Vermilion River under a regulatory system that relies primarily on self-reporting and limited monitoring, raising questions about how effectively the river is being protected.

The facilities — chemical manufacturer CARUS Corporation, the City of LaSalle’s East Side Sewage Treatment Plant, and Illinois Cement Company — operate under separate state discharge permits issued by the Illinois Environmental Protection Agency (IEPA). Together, the permits authorize industrial wastewater, treated sewage, and coal-pile runoff to enter the same stretch of river that state documents already classify as environmentally impaired.

IEPA hydrology records indicate that the Little Vermilion River reaches near-zero flow during low-water periods, meaning the stream has little natural capacity to dilute pollutants at certain times of year.

CARUS, located on Eighth Street in LaSalle, manufactures oxidizers, catalysts, and phosphate products using processed mineral ores as raw materials. Under its permit, the company is authorized to discharge approximately 1.67 million gallons per day of industrial wastewater containing reverse-osmosis reject water, filter backwash, cooling water, and stormwater runoff into the river.

Although mined ore typically contains trace heavy metals, CARUS’s permit requires routine monitoring of only one metal — zinc. Regular testing is not required for metals such as lead, mercury, arsenic, chromium, cadmium, or nickel.

CARUS is also required to monitor for per- and polyfluoroalkyl substances (PFAS), commonly known as “forever chemicals.” The permit, however, does not set numeric limits on PFAS discharges and requires only periodic reporting of detected levels.

The City of LaSalle’s East Side Sewage Treatment Plant discharges treated wastewater and sludge byproducts into the same river segment. Its permit mandates broader chemical testing than the CARUS permit, including periodic screening for multiple heavy metals and sampling for more than 100 industrial organic compounds.

Fish toxicity testing is required only four times during the multi-year permit term, while daily operations rely primarily on self-sampling and operator reporting submitted through monthly discharge monitoring reports.

State documents note that when river flow is at its lowest, discharged effluent may comprise much of the downstream water volume.

Illinois Cement Company discharges coal-pile runoff and stormwater to the Little Vermilion under a third permit. The runoff may contain suspended solids, iron, manganese, and chromium associated with coal dust and surface materials.

Sampling is required once per month, supplemented by visual inspections. Environmental specialists note that storm-runoff pollution often peaks rapidly during rainfall events, which may not be captured by infrequent sampling schedules.

Records maintained by the Illinois Pollution Control Board list the affected stretch of the Little Vermilion River as impaired for the following pollutants and conditions:

• Zinc

• Total suspended solids

• Chloride

• Phosphorus

• Altered flow conditions

• Fecal coliform bacteria
  
  

Limits for these pollutants vary among permits, and some — including chloride and PFAS — are subject only to monitoring requirements rather than enforceable discharge caps.

None of the reviewed permits include a cumulative-impact assessment examining how multiple discharge sources combine to affect overall river health.

Environmental advocates say the permit structure focuses on regulating individual facilities rather than protecting the watershed as a whole.

“The system is built to monitor paperwork compliance,” said one environmental watchdog who reviewed the permits. “But when certain pollutants aren’t tested for, and sampling only occurs once a month or less, contamination spikes can go undetected.”

IEPA officials have not responded publicly to questions regarding the absence of comprehensive metal monitoring for CARUS or the lack of discharge limits for PFAS.

Under the federal Clean Water Act, facilities must submit monthly Discharge Monitoring Reports (DMRs) documenting compliance with their permit terms. Independent field inspections by regulators are conducted periodically but not on a continuous basis.

Public records indicate that all three LaSalle facilities remain in technical compliance with their current permits, despite the Little Vermilion’s ongoing impairment classification. To date, no enforcement actions have been announced addressing the combined effects of the discharges into the river.

Water-quality experts note that streams with low or intermittent flow are particularly vulnerable to pollution because contaminants concentrate rather than disperse.

“When effluent becomes the primary water source during low flow, even permitted discharges can cause ecological stress,” one water-quality specialist said.

IEPA has not announced plans to amend the current permits to require comprehensive heavy-metal testing or to account for cumulative discharge impacts on the Little Vermilion River.

Regulators have acknowledged for decades that heavy metals from the historic M&H smelter still contaminate the Little Vermilion River. But rather than use modern testing to determine whether current industries are adding new pollution to the river, state permits largely assume metals are a “legacy problem” — eliminating routine metal monitoring requirements for modern dischargers like CARUS. The absence of testing prevents regulators and the public from knowing whether present-day facilities are worsening a contamination problem already attributed to past industrial activity.