South Complex upgrades have a positive impact on aquatic life

Aquatic life improvements downstream of the Robert W. Hite Treatment Facility (RWHTF) outfalls are directly tied to lower final effluent ammonia concentrations, following completion of the South Secondary Improvements Project (see story on opposite page).

The conclusion regarding the positive impact on aquatic life is supported by data collected by members of the Metro District’s water quality staff, who routinely use kick nets to conduct macroinvertebrate studies at various locations along the South Platte River. The samples gathered are then evaluated according to the Water Quality Control Division’s Multi-Metric Index (MMI).

Studies show the MMI numbers in 2015 and 2016 were the highest at the two monitoring sites closest to the RWHTF outfalls since monitoring began 25 years ago. The Index is largely based on the overall diversity of macroinvertebrate taxa and the percentage of sensitive species present (i.e., mayflies, dragonflies, and caddisflies).

South Platte River downstream of the Robert W. Hite Treatment Facility