DENVER, CO — A dewatering project near Denver has achieved a special distinction for its beneficial contributions to sustainable infrastructure.

The City of Westminster's Big Dry Creek Wastewater Treatment Facility (BDCWWTF) Dewatering project earned an Envision Bronze verification. The facility is designed for biochemical oxygen demand removal, nitrification and denitrification, and limited phosphorous removal. The project provides the city with new solids dewatering equipment and facilities, an improved central handling system, enhanced nutrient removal, biosolid beneficial use optimization at the city’s farm, operational optimization, and campus-wide improvements throughout and around the facility.

This project is the first Envision achievement for Westminster. By using Envision on this project, the city is affirming its commitment to sustainability and the use of Envision as an important tool to improve the sustainable performance of its infrastructure assets. The city worked closely with HDR on the project.

“Sustainability and safe, reliable service are top priorities for our residents and will be a continued focus of our strategic infrastructure investments,” said Max Kirschbaum, City of Westminster’s Public Works and Utilities Director.

The Envision framework assesses project sustainability across five categories: Quality of Life, Leadership, Resource Allocation, Natural World, and Climate and Resilience. These areas contribute to positive social, economic, and environmental impacts on a community during the planning, design, and construction of infrastructure projects.

Key factors contributing to the treatment facility's bronze verification:

Biosolids are a byproduct of the wastewater treatment process. Because they are nutrient rich, they can be used as fertilizer to increase crop yields. However, the Environmental Protection Agency reports that only 50 percent of all biosolids in the U.S. are captured and put to beneficial use, with the remaining 50 percent sent to landfills or incinerated. One of the main purposes of the BDCWWTF Solids Dewatering Project is to reduce the water content and nitrogen load of the city’s biosolids. As a result, more biosolids from the city’s wastewater treatment processes can be used as fertilizer by the city’s Strasburg Natural Resource Farm and other contracted farms nearby.By reducing the water content of biosolids and allowing more material to be applied to the same acreage, the city is able to reduce the number of truck trips to the SNRF and other contracted farms by 75 percent. The effect is a more efficient use of employee time and reduced storage requirements at the site when farmland is unavailable for biosolids application.

If not for this project, it is anticipated that by 2035 an increase of biosolids produced at the facility would lead to significant composting expenditures, further burdening utility ratepayers. Instead, this project will lead to savings of $100,000 per year, ensuring ratepayers are not unduly burdened in the future.

The Solids Dewatering Building — a key component of this project — was designed with future loading in mind, reducing the need for a redesign in the near term, and leading to reduced maintenance spending. In addition to the design and construction of the building, other campus-wide improvements and updates provide flexibility, durability, and resiliency for the facility.