Fecal matter elevated in South Platte River
Colorado health officials this week declared water quality in the South Platte River as it flows through Denver highly deficient, pointing to E. coli contamination at levels up to 137 times higher than a federal safety limit.
This intestinal bacteria indicates fecal matter and other pollution from runoff after melting snow and rain sweeps Denver pollution through drainage pipes into the river. To deal with the problem, the Colorado Department of Public Health and the Environment has imposed, in a permit taking effect next month, stricter requirements for managing runoff water pollution.
But Denver officials are
fighting those requirements and twice petitioned the state health department to relax the new permit.
“What the new requirements do is drastically increase the amount of expensive system maintenance beyond what could make a meaningful impact on E. coli concentrations,” city spokeswoman Nancy Kuhn said.
Colorado public health officials last month rejected Denver’s latest appeal. They issued a statement standing by their demands for the city to reduce its water pollution, saying the agency hopes to avoid litigation.
A more aggressive approach is required, state health officials said in the statement, “because the South Platte remains in bad shape for pathogens.”
Denver officials told The Denver Post on Wednesday “no lawsuit has been filed” challenging the permit in state court and that they are “having conversations with the state on five or so new requirements with the hope of reaching compromise.”
Sampling of South Platte River water by state inspectors found E. coli levels exceeding the federal recreational safety limit of 126 colony-forming units (cfu) per 100 milliliters. The river contamination in 2018 reached as high as 17,300 cfu. And where the South Platte flows northward out of Denver, E. coli that year measured 2,420 cfu on several summer days — a time when more people are likely to be exposed to urban runoff and river water.
The E. coli and other pollution come from multiple sources — including dog waste, industrial plants, homeless camps and malfunctioning septic systems — that are whisked from paved surfaces into runoff.
“Denver’s storm sewer system is a clear part of the problem,” CDPHE permitting officials said in an email.
When inspectors in 2019 sampled water flowing out of city drainage “outfall” pipes into the South Platte, they detected E. coli at levels as high as 1,970 cfu from one pipe and 8,400 cfu from another, state data shows.
Denver Water and Trout Unlimited for decades have been trying to restore the South Platte to a healthier condition. And for Denver residents, in particular, the behind-the-scenes haggling over requirements in what is called an MS4 permit can be frustrating.
“We don’t know how to navigate these water quality issues,” said Shaina Oliver, a member of the grassroots groups EcoMadres and Moms Clean Air Force, which represent low-income people often hit hardest by pollution. Oliver pointed out that children play in runoff water puddles and creeks.
“For me as an indigenous person, water is sacred,” she said. “It is unfathomable, our disregard for water.”
The persistence of urban runoff problems in Denver and this latest state-city legal wrangling reflect the wide difficulties nationwide in dealing with cities’ water pollution. The Environmental Protection Agency has identified stormwater runoff from cities as the nation’s main source of water pollution degrading creeks, ponds and rivers. Managing water in cities can cost billions.
Yet water quality increasingly is linked by city dwellers with their quality of life. Denver officials in recent years committed to reengineering urban stormwater drainage as “green infrastructure,” which requires reworking urban landscapes to incorporate more unpaved greenspace that can serve as a sponge to absorb runoff water and filter out contaminants. They planned to open up natural waterway corridors buried under 20th-century development.
The permits that the EPA and state health departments issue to cities regulating MS4 — municipal separate stormwater sewer systems — require action to meet EPA standards under the federal Clean Water Act. Denver’s new permit requires ramped-up work to reduce pollution flowing into waterways including the Cherry Creek, the Sand Creek and the South Platte River to “the maximum extent practicable.”
Under the new permit, Denver officials must ensure environmentally friendly designs in construction projects, development and at factories. They would have to monitor and reduce the water pollution reaching Barr Lake and Milton Reservoir northeast of the city, which store water used to irrigate food crops.
Denver “understands” that the requirements for construction, development and industry “are critical elements of reducing pollution from stormwater systems,” said Kuhn, of the city’s Department of Transportation and Infrastructure.
But Denver would have to spend $500,000 a year for five full-time staffers to handle permit compliance, and this would divert from work to clean up urban drainage, Kuhn said.
“Denver has never opposed the numeric limit of 126 cfu per 100 milliliters,” she said, but opposes “the specific measures that CDPHE is mandating to achieve that limit.”
A consultant analyzing Denver stormwater runoff in 2018 proposed, in a document included in a 419-page state fact sheet accompanying the new permit, a comprehensive effort to slow drainage flows, treating runoff water as a useful resource for regreening in a semi-arid area.
He recommended wide use of low-cost measures such as flattening crowned streets, installing small dams in alleys to redirect culvert-bound gushing runoff, and converting sidewalks to “semi-pervious” surfaces that let water sink between stones into the soil.
Denver’s population growth and development boom have worked against greening to improve water quality. Developers have paved over more surfaces, leaving Denver as one of the nation’s most paved-over cities — especially in newly developed areas — sluicing away runoff water at high velocity without removing contaminants.
Denver officials directed contractors at the city’s new Globeville Landing outfall drainage pipe, in a park built over a former toxic dump site, to install an ultraviolet light. This light, city officials say, zaps away more than 90% of E. coli before runoff water reaches the river.
Wild animals such as raccoons in storm sewers add to the fecal pollution contaminating runoff, Kuhn said, and “dog waste that people don’t pick up is a huge problem and a significant source of E. coli.”
Colorado health officials for years pressed Colorado Springs to reduce the stormwater runoff and other pollution of Fountain Creek, and a lawsuit filed by Pueblo, lower in the watershed, dragged on for more than a decade until the EPA negotiated a settlement.
“We have a vision for clean water, for people to drink and swim in where they work and play,” said Trisha Oeth, the state health department’s acting environmental programs policy adviser.
“We see that the use of ‘green infrastructure’ can be promising, and in some cases it is a better way to improve water quality” compared with “mechanical” water-cleaning treatments, Oeth said. “We want to encourage that and allow flexibility for that to be used.”
State officials acknowledged they lack legal authority over Denver’s development decisions regarding densification, open space and greenspace.
“But we see a problem with the elevated levels of E. coli,” Oeth said. “We are all contributors to that, us as individuals, businesses, all of Denver. We also see all of us as part of the solution. We are hopeful that we can continue to work with Denver.”