2022 ENR Awards go to South AdamsAdams County Water and Sanitation District Pellet Softening and Disinfection Project
The Excellence in Safety Award is now in its tenth year. An independent panel of safety experts considered many factors in their decisions, including a project’s overall safety program, OSHA recordable incident rate, lost time accident rate and total work hours on the job.
Moltz Construction’s South Adams County Water and Sanitation District Pellet Softening and Disinfection won the Award of Merit: Excellence in Safety and the Best Project Award: Excellence in Sustainability for the Regions of Colorado, Wyoming, and the Dakotas.
More about the South Adams project:
The 12 alluvial wells that supply the South Adams County Water and Sanitation District’s 66,000 customers produce severely hard water, requiring local homeowners to frequently replace plumbing and water heaters and purchase costly in-home softeners that release corrosive brine waste into the sewer. The softeners also contribute to discharges of high dissolved solids from the district’s wastewater treatment plant.
Mineral pellet softening technology, a proven treatment process in Europe, offered a compact, cost-effective way to rectify the hardness issues and meet the district’s finished water goals. That led to the construction of an 18-million-gallon-per-day water softening and filtration plant—the largest facility of its type in the U.S. and the first in the world to utilize load cells to remotely manage pellet size and inventory. The load cells allow the facility to be unattended for half of the day, resulting in lower personnel costs that help reduce customers’ softening rates. In addition, spent pellets can be beneficially reused in a variety of local applications.
Constructed out of a prefabricated structure at the district’s water treatment facility, the pellet-softening operation’s electrical infrastructure is almost entirely above ground. Advanced modeling technology aided in precisely locating wireway and duct bank locations. To minimize onsite concrete work and accelerate construction, the pellet-softening train’s eight filters were prefabricated inside stainless-steel vessels, then delivered in sequence to limit onsite storage needs. Chemical-feed equipment is positioned on corrosion-minimizing housekeeping pads while valves are located within easy reach of operators.
As the project unfolded at the height of the COVID-19 pandemic, the project team followed strict guidelines to minimize spread of the virus. In addition to social distancing, mask use and smaller crew sizes, the workers received a daily flow chart that included self-diagnosing prompts, temperature records and mandatory steps to be fulfilled before being permitted to remain in the field. Mock accident drills also helped prepare teams for any kind of emergency.
The construction team offered safety-enhancing practices to be incorporated into plant operations, such as routing softened water plumbing to the calibration columns. This allows clean water to push through the pumps, minimizing operator exposure to hazardous chemicals. All piping and valves are clearly labeled with tagging numbers to simplify and assist in staff training and troubleshooting sessions.
The new system was constructed with no recordable incidents or lost-time accidents in more than 150,000 staff hours, and with no disruption to the water treatment plant’s operations and services. Once the installation was complete, vigilant testing allowed the district to adjust and ultimately increase the filter-loading rate from the original design capacity, eliminating the need to construct two additional filters and creating space for a future pellet-grinding installation.