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Which Arizona creeks, lakes, rivers have the most contaminants?


“Don’t poo in the water” is a reminder one would think wouldn’t be needed for adults.

Arizona State Parks regularly issues that reminder.

There are 11 sites that are on the Arizona Department of Environmental Quality’s surface water quality remediation sites. If you want to avoid the states most scrutinized Arizona places, based on water concerns, avoid state parks and other places with bodies of water near these areas.

Michelle Thompson, spokesperson for Arizona State Parks, said the top five most popular parks in the state, in terms of Fiscal 2021 visitation, with water were Lake Havasu, Slide Rock, Dead Horse Ranch, Patagonia Lake, and Fool Hollow Lake Recreation Area.

Since Slide Rock and Patagonia Lake are near two main mitigation sites, it appears the public either doesn’t know or doesn’t consider these risks barriers to choosing these Arizona State Parks for recreation.

“We do not have a rating system for our parks with water,” Thompson said. “We work closely with the Arizona Department of Environmental Quality. We advise our visitors to pack in what they bring to the park, including dog waste. We have created several great resources about litter walks, easy ways to clean up after your pet, and how to be responsible stewards of the lands and the parks.”

Humboldt Well

Located in the Patagonia Mountains, approximately 6.5 miles southeast of Patagonia Highway along Flux Canyon Road, Santa Cruz County, this well is about 20 miles northeast of Nogales and about 12 miles from Patagonia Lake State Park.

Discovered as a site in need of analysis in 2009, the well affects water running through Humboldt Canyon. The well was capped in the early 2000s.
Cadmium, copper, zinc and low pH in surface water have affected aquatic and land wildlife in the canyon.

While analysis shows there is little to no health risk unless there is contact with skin or ingestion of contaminated soil, groundwater is only safe if filtered by a public water system. Private wells in the vicinity should be tested.

Artesian groundwater well water discharged into Humboldt Canyon, a tributary to Alum Gulch. Permanent remediation work was set to begin last October.

Oak Creek
This picturesque waterway runs down out of the higher parts of Coconino National Forest, near Flagstaff, through the Verde Valley, eventually joining the Verde River southeast of Cottonwood.

It runs through Oak Creek Canyon and the city of Sedona along State Route 89A and provides swimming access at many points, including near Red Rock State Park and Slide Rock State Park.

The Verde River feeds into the Salt River, itself providing water to millions of people living in and around the Valley.

Documented problems with Escherichia coliform, or E.coli, contamination in Oak Creek go back decades. In its 2006/2008 Clean Water Act 305(b) Assessment Report, ADEQ listed Oak Creek as impaired for exceeding the E.coli water quality standards.

ADEQ has engaged many partners to help alleviate sources of E.coli contamination in Oak Creek to improve 50-plus miles of affected stream of Oak Creek.

This included closure and rehabilitation of more than 120 informal social trails, which previously caused soil disturbances and erosion that brought E.coli into the creek.

Installation of barriers to reduce unpermitted parking along State Route 89A were to minimize social trail use, as well as improve visitor safety. Construction of a fence at Slide Rock State Park was meant to prevent unpermitted visitation, reduce potential impacts on water quality due to crowds and improve visitor safety.

Installation of pet waste stations along established trails to encourage cleaning up after pets and keeping dog waste out of the creek

Support of litter clean-up events, which have already removed thousands of pounds of trash that would have otherwise attracted wildlife and, along with it, fecal waste, reports state.

However, keeping contaminants out of Oak Creek is an uphill battle. In the summer of 2007 alone, Arizona State Parks closed Slide Rock State Park, up-creek from Sedona, more than 12 times due to fecal bacteria contamination.

In the summer of 2020, a contractor working on sewer repair mistakenly dumped 20,000 gallons of raw sewage into the creek along the southern city limits of Sedona.

Three-R Canyon
Three-R Canyon is one of the nine mines on the ADEQ mitigation list.
Located in the Patagonia Mountains, about 14 miles northeast of Nogales, adjacent to Three-R Canyon, this location is in Santa Cruz County. According to ADEQ, it was discovered to have water issues in January 1996, though intermittent mining stopped by 1956.

The impaired surface water body is Three-R Canyon. There is no substantial risk to contaminated soil in the area unless that soil is ingested.

ADEQ contractor completed a preliminary site assessment in 2019, began implementing remediation in November 2020 and effectiveness monitoring will continue in 2022 and 2023.

Also on the remediation list are the Cash, Eugene, Exposed Reef, Gibson, McCleur, McKinley Mill, (Wetland) Poland Walker Tunnel and Storm Cloud mines. The closest of these to the Valley is probably Gibson Mine, located east of Top-Of-The-World and Superior, or a cluster of mines located south of Prescott. Both are about 100 miles from Sun City.