Water regulators in Colorado are considering changing groundwater drainage permits

Colorado environmental regulators could eliminate rules that prevent some of the polluted groundwater from being discharged into the state's rivers and streams, alarming environmentalists who fear the change could further harm already polluted urban waterways.

The Colorado Department of Public Health and Environment's water quality control division has proposed eliminating a permitting system that governs how underground structure owners handle contaminated groundwater. The change would allow building owners to discharge groundwater contaminated with PFAS chemicals, arsenic and other pollutants directly into stormwater systems without treatment.

Environmentalists and former Water Quality Control Division employees fear the change could harm the water quality of the South Platte River and its tributary Cherry Creek as they flow through Denver along with other Front Range waterways.

“We’re talking about some really bad toxins,” said Josh Kuhn, senior water campaign manager for Conservation Colorado.

The permits in question regulate underground drainage: the process of removing groundwater that enters underground structures such as parking garages and basements. CDPHE oversees 113 long-term drainage permits that require building owners to measure how much water they discharge, test the water for contaminants and treat the water if contaminant levels exceed contamination limits.

If the policy changes are approved, all permitting, reporting and treatment requirements for drainage systems would be eliminated. State water quality officials said the permitting system is a burden on building owners and that lifting the regulations would not have a major impact on water health. The Water Quality Division is accepting public comments on the proposed change through Saturday.

Most of the 113 approved buildings are in downtown Denver, but some are in Boulder and other Front Range communities. The Colorado Convention Center, the nearby Hyatt Regency Denver Hotel and many other large downtown buildings have permits for their drainage systems.

The systems extract groundwater and forward it to rainwater systems. In Denver, all stormwater flows to the South Platte, which downstream communities use for drinking water. The river has suffered from poor water quality for decades.

Groundwater in urban areas is often contaminated by the chemicals used in modern life – such as fertilizers, toxic PFAS, so-called “forever chemicals”, firefighting foam and gasoline – as well as naturally occurring metals such as arsenic and selenium.

According to CDPHE data compiled by Meg Parish, an attorney with the Environmental Integrity Project who previously worked for the Colorado Water Quality Division where she managed permitting, many facilities with drainage systems treat water well above water quality standards . Without the permit system, facilities would not be required to treat the water and could instead dump the contaminated water into the stormwater system and ultimately the river.

Under current permits, for example, a home in Highland discharges water containing 202 micrograms of arsenic per liter into the stormwater system – more than 10,000 times the water quality standard of 0.02 micrograms per liter for water and human life. A retirement home for priests in southeast Denver is treating water with nearly four times as much uranium as the water quality standard allows.

And a parking garage on Wewatta Street next to Cherry Creek treats water with about 15 times the concentration of PFAS required by state guidelines, which are looser than newly announced federal drinking water standards.

CDPHE Official: 'Very Low Risk' With Changes

Water Quality Division Director Nicole Rowan said eliminating the permits would have a negligible impact on South Platte's water quality because the number of permitted buildings is small and they don't discharge as much water.

“We believe this proposed policy change to drainage permits poses very little risk to overall water policy,” Rowan said.

The change would affect only a small portion of the thousands of water quality permits the department oversees, Rowan said. Plus, she said, groundwater will eventually end up in the river with or without a permit.

In Denver, buildings typically emit about 5 gallons per minute, Rowan said. That's about 8 acre-feet per year per building flowing into the South Platte, which contains about 342,000 acre-feet of water. An acre-foot is the amount of water needed to cover one acre – about the size of a football field – with one foot of water.

The water quality department has raised concerns over the last year about the affordability of complying with permitting requirements, particularly when it comes to affordable housing projects, Rowan said.

However, concerns about affordability should not result in canceling the entire approval process, Parish said. The current system allows developers and building owners to request exceptions to the requirements, such as when the required treatment is excessively expensive or technically impossible, she said.

“I think that’s what developers should spend their money on,” Parish said. “But if the argument is that this treatment is too expensive and they can’t afford it – then there are legal ways to address it.”

“Short-term comfort is the priority”

Conservation Colorado advocates are particularly concerned about planned major renovations at the Elitch Gardens theme and water park and around Ball Arena – two large sites that lie at the center of the confluence of South Platte and Cherry Creek.

If the permit system is overridden, some of the progress made by state lawmakers and federal regulators to limit the spread of PFAS will be undone, Kuhn said.

“Short-term convenience and cost reduction take priority over long-term health and environmental protection,” he said.

The change would also violate state and federal clean water laws, Kuhn and Parish said. This could open the department to litigation and create legal uncertainty in the regulatory process, Kuhn said.