Regulatory Assistance

Over the years, our staff has developed a close relationship with many of the regulatory officials in the Water Quality Control Division. Whether it’s helping to navigate the Site Application process, set-up an industrial pre-treatment program, complete an Environmental Report to meet USDA or State requirements, answer questions about reuse, negotiate discharge permit limitations, or calculate preliminary effluent limits, Indigo Water Group has you covered.

Our staff has assisted numerous municipalities and special districts navigate State regulatory requirements. We recently renegotiated a discharge permit for a small Christian dude ranch near Estes Park. Because of our hard work, their new permit no longer contains a nitrate limit and their anti-degradation limit for ammonia of 0.4 mg/L was raised to match their lowest monthly limit of 1.6 mg/L.

Indigo Water Group can assist water districts with understanding the Clean Water Act including recently promulgated regulations including LT2ESWTR and Stage 2 DBPR. Our staff, in conjunction with Integra Engineering, worked closely with Montezuma Water Company in Delores, Colorado to limit disinfection by-product formation in their distribution system.

Preliminary Effluent Limits

Clean WaterOne of the big uncertainties with wastewater treatment plant expansions is the discharge limits that will have to be met. Indigo Water Group can evaluate your historic effluent and receiving water data and calculate estimated Preliminary Effluent Limits (PELs) for metals, fecal coliforms, and ammonia. As the State converts from the Colorado Ammonia Model (CAM) to the new Ammonia Toxicity Model (AMTOX), permit limits for established treatment facilities will change. Indigo Water Group can estimate PEL’s for ammonia with the AMTOX model as part of the Utility Planning process.

We can double-check the State’s PEL calculations. Occasionally, errors are made or the municipality or District possesses additional data that were not available to the State. Double-checking PEL calculations could save tens of thousands of dollars in compliance costs.

Discharge Permit Review

The discharge permit is a legal obligation between the Owner and the State of Colorado. The permit sets limits on effluent concentrations for various parameters and gives the rated capacity of the treatment plant. We operate all of our facilities to meet or exceed permit expectations.

At the same time, we believe that the Owner should understand their obligations under the permit. At the beginning of each new project, we meet with the Owner to review the discharge permit. We’ll explain any terms that are unfamiliar and establish a regular visitation and sampling schedule for the facility.

We’ll also review the previous three years of DMR and operating data. The review will determine the maximum month flow and load and compare them to the permitted capacity of the facility. We’ll confirm that flows, loads, generation rates, and ratios between parameters are within expected ranges.

Project Highlight

We recently negotiated new discharge permits for the Town of Erie, the City of Lafayette, and Jalisco International. We worked closely with CDOT to successfully obtain a temporary modification to the arsenic standard for Segment 14 of the South Platte River.