2017-05-11_PERMIT FILE - C1981012 ‎(18)‎

• Permit No: C1981012
• IBM Index Class Name: Permit File
• Doc Date: 5/11/2017
• Section_Exhibit Name: Exhibit 22 NPDES Permit
• Media Type: D
• Archive: No

In TRIM
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Fact Sheet- Page 25, Permit No. C00000906
sediment yield from pre -mined, undisturbed conditions. The Sediment Control Plan must be approved
by the permitting authority (DRMS) and be incorporated into the permit as an effluent limitation. The
Sediment Control Plan must identify best management practices (BMPs) and also must describe design
specifications, construction specifications, maintenance schedules, criteria for inspection, as well as
expected performance and longevity of the best management practices.
b. Using watershed models, the operator must demonstrate that implementation of the Sediment Control
Plan will result in average annual sediment yields that will not be greater than the sediment yield
levels from pre -mined, undisturbed conditions. The operator must use the same watershed model that
was, or will be, used to acquire the Surface Mining Control and Reclamation Act (SMCRA) permit.
c. The operator must design, implement, and maintain BMPs in the manner specified in the Sediment
Control Plan.
The permittee is responsible for submitting proof that the Sediment Control Plan required under Subpart H has
been approved by the Colorado Division of Reclamation, Mining, and Safety, and is implemented at the facility.
The operator must design, implement, and maintain BMPs in the manner specified in, or to maintain the
requirements of, the Sediment Control Plan.
2. Practice -based Effluent Limitations (Outfalls 004, 007, 008, 010, and 011)
As discussed in the Stormwater Management Plan (SWMP) section below, the effluent limitations contained in
this permit are located in a section separate from the SWMP, thereby differentiating effluent limitations from
other terms and conditions of the permit.
Practice -based effluent limits (PBELs) are technology-based effluent limits, which are required for all CDPS
permits. The PBELs, and any applicable ELGs, correspond to the required levels of technology-based control
(BPT, BCT, BAT) for various discharges under the Colorado Water Quality Control Act.
The PBELs identified in this permit are applicable to stormwater-only discharges (both those that are subject to
a federal ELG and those that are not), to address potential impacts to receiving water quality from such
discharges. The PBELs in this permit are largely the same as those included in the previous permit with the
following additions:
a. Minimize Exposure - the renewal permit defines the term "minimize" to provide the permittee with a
clear expectation for the level of performance of control measures implemented to achieve the
practice -based effluent limits that require the permittee to "minimize" pollutants. For such practice -
based effluent limits, the term minimize means to "reduce and/or eliminate to the extent achievable
using control measures (including best management practices) that are technologically and
economically practicable in light of best industry practice."
Minimizing exposure prevents pollutants from coming into contact with precipitation and can reduce
the need for control measures to treat or otherwise reduce pollutants in stormwater runoff. As such,
this is one of the most important control options.
b. Salt Storage Piles or Piles Containing Salt - Salt storage piles are prevalent across the country. The
permit requires that permittees adequately control salt piles to prevent aquatic effects resulting from
stormwater runoff from such piles. The permittee must enclose or cover storage piles of salt, or piles
containing salt, used for deicing or other commercial or industrial purposes, including maintenance of
paved surfaces, and implement appropriate measures to minimize exposure resulting from adding to or
removing materials from the pile. Preventing exposure of piles to stormwater or run-on also eliminates
the economic loss from materials being dissolved and washed away.
c. Waste, Garbage and Floatable Debris - In addition to other stormwater pollutants, the permittee must
minimize the discharge of waste, garbage, and floatable debris, pollutants associated with most if not
all industrial activities, so that these pollutants are not ultimately discharged to receiving waters.
Trash and floating debris in waterways have become significant pollutants, especially near areas where
a large volume of trash can be generated in a concentrated area. Trash can cause physical