In 2012, Arizona listed Miller Creek as impaired by E. coli from human waste. 8 years later, Prescott groups built a public restroom, cutting E. coli levels by 13%

Clean waterways depend not only on natural conditions but also on access to basic facilities that can help prevent pollution. In Prescott, Arizona, a public restroom project along Miller Creek was developed in response to concerns about E. coli contamination linked to human waste.

The project brought together local organizations, the City of Prescott and state funding to address a specific water quality problem along a well-used creek corridor.

Miller Creek and the E. coli Problem

Miller Creek is an intermittent tributary of Granite Creek in Prescott, Arizona. The Granite Creek watershed lies in Yavapai County and forms part of the headwater system of the Verde River.


The Arizona Department of Environmental Quality (ADEQ) placed one reach of Miller Creek, discovered as waterbody ID 15060202-767, to the Clean Water Act (CWA) Section 303(d) list of impaired waters in 2012 because of E. coli.

The creek had been examined as exceeding the full body contact single sample water quality standard of 235 colony-forming units per 100 milliliters (cfu/100 mL), with over one exceedance occurring in a consecutive three-year duration.

Proofs pointed mainly toward human sources of the contamination. In 2010, microbial source tracking (MST) was conducted as part of the Granite Creek Watershed Improvement Plan. The approach uses genetic analysis of Bacteroides, a type of bacteria found in mammalian fecal matter, to identify the animal sources of fecal bacteria found in waterways.

In the watershed, 46 samples were taken from 23 places, and 91% tested positive for the human genetic marker. Miller Creek featured a similar pattern: 10 of the 11 MST samples collected there, or 91%, tested positive for the human marker.

Lack of Restrooms Identified as a Concern

The Granite Creek Watershed Improvement Plan discovered the absence of public restrooms as a water quality concern.

As per the plan, the Miller Creek Trail is part of the City of Prescott’s Greenways Trail System. It runs alongside the creek and connects with the downtown trail at the point where Miller Creek meets Granite Creek.

The creek corridor and trail are widely utilized by people without stable housing for travel, gathering and camping because the area offers opportunities for more secluded shelter. Several people without stable housing spend considerable time along the creeks, where bathrooms are unavailable. This was discovered as a potential contributor to fecal contamination in Miller Creek.

The issue offered an opportunity to address water quality by enhancing access to sanitation facilities near the creek.

How the Restroom Project Began

The Watershed Improvement Plan was developed through almost four years of work led by Prescott Creeks, with funding and technical support from ADEQ, alongside numerous watershed stakeholders.

In 2016, the Coalition for Compassion and Justice (CCJ) acquired property next to Miller Creek. The organization later approached Prescott Creeks to ask how it could serve as a responsible steward of the creek.

That conversation eventually resulted in the concept of a public restroom near Miller Creek.

ADEQ supplied financial support through a CWA Section 319(h) grant for the water quality improvement project. Funding was obtained in September 2017, after which monitoring started to establish baseline conditions before the restroom was constructed.

The Butte Creek Restoration Council played a significant role in collecting the baseline data. Project plans were completed toward the conclusion of 2017, while permits were obtained through the City of Prescott in 2018.

Building a Public Restroom

Construction of the restroom happened from January through April 2019. After the work was completed, a ribbon-cutting ceremony recognized the partners, funders and other participants involved in the project.

The completed structure had two individual restrooms, providing capacity for potential users. It was built to comply with the Americans with Disabilities Act of 1990 and uses durable components designed to resist vandalism.

The facility also includes door sensors on both bathroom doors. These sensors make it possible to track how many people use the restrooms.

The project goes beyond the physical construction of the facility. Educational and outreach efforts were introduced to increase awareness about pollution impacting Miller, Butte and Granite creeks.

These attempts included directional and interpretive signs, presentations and informational meetings involving CCJ clients and staff, members of the public, water advocacy organizations and the City council. Press releases were also used to communicate the work to a wider audience.

Water Quality Improvements Follow

The restroom and interpretive signage produced measurable improvements in Miller Creek's water quality.

As per the project data, the work resulted in a 13% reduction in E. coli levels in the creek. As a result, Miller Creek was provisionally delisted for E. coli for full body contact.

Later monitoring offered further evidence of improvement. Water quality measurements collected in 2022 and 2023 showed a consistent reduction in E. coli concentrations.

The recorded concentrations fell below the applicable full body contact standard of 235 cfu/100 mL. The most recent water quality data showed that Miller Creek is no longer impaired and will be removed from Arizona’s list of impaired waters.

Long-Term Maintenance

The restroom was made with a life expectancy of well over 20 years. Project partners also agreed to maintain the facility in full working order, extending their commitment beyond the original scope of the project.

Operating expenses are anticipated to approach $200,000 over the life of the project when utilities, consumable supplies, cleaning and monitoring are included.

The Miller Creek project therefore combines a relatively direct solution— providing access to public restrooms with education, monitoring and long-term maintenance.

From its listing as an impaired water for E. coli to the subsequent reduction in contamination, Miller Creek's restoration effort features how local infrastructure and coordinated water quality work can lead to measurable improvements in a creek affected by human waste.

Source: NONPOINT SOURCE SUCCESS STORY

FAQs:

Q1. What is Miller Creek?

Miller Creek is an intermittent tributary of Granite Creek in Prescott, Arizona. It is located within the Granite Creek watershed in Yavapai County.

Q2. Why was Miller Creek considered impaired?

The Arizona Department of Environmental Quality listed one reach of Miller Creek as impaired for E. coli in 2012. The creek exceeded the applicable full body contact water quality standard.