How Can We Help?
- Site Application
- Preliminary Effluent Limit Calculation or
- AMMTOX modeling
- Environmental Reports
- Industrial Pretreatment Programs
- Septage Receiving
- Safe Drinking Water Act Requirements
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
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
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
One 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.