2009-03-06_PERMIT FILE - C1981012A ‎(6)‎

• Permit No: C1981012A
• IBM Index Class Name: Permit File
• Doc Date: 3/6/2009
• Section_Exhibit Name: Exhibit 22 NPDES Permit
• Media Type: D
• Archive: Yes

•
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT, Water Quality Control Division
Rationale - Page 19, Permit No. CO-0000906
V.
vi.
accordance with the compliance schedule allowing time for monitoring well installation or modifications to the
permit, as appropriate.
c ncen in the pert to
TDS as peccified intRthe water
egulation
Total Dissolved Solids
which is calculated dissolved based on the limit will be plced
quality standard,
41, The Basic Standards for Ground Water.
Because the TDS standard and therefore the TDS permit limit is based on the upgradient water quality, TDS
limits cannot be imposed until groundwater monitoring has been completed. Thus, monitoring, only, is
required at all the groundwater monitoring wells (i.e., 050A, 050B, 050C and 050D) until sufficient data are
collected and/or the next round of permitting. Note that monitoring requirements become effective in
accordance with the compliance schedule allowing time for monitoring well installation or modifications to the
permit, as appropriate.
Metals - The dissolved metals limits are placed in the permit to protect these particular groundwater standards
found in Regulation 41, The Basic Standards for Ground Water.
Metals limits are imposed at the downgradient groundwater monitoring wells 050B, 050C and 050D, with an
appropriate effective date for the limits and monitoring, only, required prior to the limits' effective date.
Monitoring, only, is also required at the upgradient groundwater monitoring well 050A. Note that monitoring
requirements become effective in accordance with the compliance schedule allowing time for monitoring well
installation or modifications to the permit, as appropriate.
For metals with groundwater standards, monitoring will be based on the dissolved method of analysis because
the standards are human health and/or drinking water-based standards. Testing for dissolved mercury must be
accomplished using low-level detection methods.
4. Stormwater - Stormwater discharge permits are required./or active and inactive coal mining facilities as covered under
Standard Industrial Classification (SIC) Code 12.
Division records indicate that New Elk Coal Co LLC has coverage for stormwater discharges from the New Elk Mine
under a General Stormwater Discharge Permit, number COR-040192. Stormwater permitting issues for this mine will
be handled separately by the Division's Stormwater Unit.
5. Economic Reasonableness Evaluation - Section 25-8-503(8) of the revised (June 1985) Colorado Water Quality Control
Act required the Division to "determine whether or not any or all of the water quality standard based effluent limitations
are reasonably related to the economic, environmental, public health and energy impacts to the public and affected
persons, and are in furtherance of the policies set forth in sections 25-8-192 and 25-8-104. "
The Colorado Discharge Permit System Regulations, Regulation No. 61, further define this requirement under 61.11 and
state: "Where economic, environmental, public health and energy impacts to the public and affected persons have been
considered in the classifications and standards setting process, permits written to meet the standards may be presumed
to have taken into consideration economic factors unless:
a. A new permit is issued where the discharge was not in existence at the time of the classification and standards
rulemaking, or
b. In the case of a continuing discharge, additional information or factors have emerged that were not anticipated or
considered at the time of the classification and standards rulemaking.
The Water Quality Control Commission, during their proceedings to adopt the Classifications and Numeric Standards
for Arkansas River Basin, considered the economic reasonableness of imposing the classification and standards
discussed in Section 11 of Appendix A. Since this is not a new discharger and no new information has been presented
regarding the classifications and standards, the water quality standard-based effluent limitations of this permit are
determined to be reasonably related to the economic, environmental, public health and energy impacts to the public and
affected persons in accordance with Section 61.11 of the Colorado Discharge Permit System Regulations. If the
permittee disagrees with this finding, pursuant to 61. 11 (b) (ii), the permittee should submit all pertinent information to
the Division during the public notice period.
B. Monitoring