2008-09-15_PERMIT FILE - C1992081

• Permit No: C1992081
• IBM Index Class Name: Permit File
• Doc Date: 9/15/2008
• Doc Name: CDPS Permit
• Section_Exhibit Name: Tab 13 Appendix 13-1
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OFPUBLICHEALTHAND ENVIRONMENT, Water Quality Control Division
Rationale, Page 2, COG-0850000 Coal Mining General Permit
B. Application
Dischargers can apply for coverage under this general permit once the permit is issued. Holders of certifications under the
administratively extended Coal Mining Permit (COG-0850000) will automatically be transferred to this new general permit.
Their coverage will be transferred to the new general permit without a lapse of coverage (i.e. discharging without a permit) and
without loss of fee payments. The permittee will have 90 days, from the date of transfer, to comply with any new terms and
conditions of this general permit. For all others, the owner or operator of the site shall submit one original completed
application and a copy, including a signed certification that the SWMP is complete at least thirty days prior to the
commencement of mining activities.
III. EFFL UENT LIMITATIONS
A. General Effluent Limitations and Monitoring Requirements
Numeric effluent limitations are imposed for pollattants that are specific to the discharges covered, and are shown in Tables III-1
through III-6. Some of these limits are based on the EPA Federal Efjluent Guidelines for the applicable point source
category and are described below. The certification will state which conditions apply to which outfalls, based on the nature
of the discharge. Note that any parameter that is determined to be asite-specific pollutant of concern may be added to the
discharge certification.
1. Sur face Runoff or Non-Coal Mining Related Wastestreams -Table III-1 contains the general limitations and monitoring
requirements for wastewater from coal mining sites that are not directly related to mining activities.
Table III-I: Effluent Limitations and Monitoring Requirements for Outfalls Comprised of Surface Runoff orNon-Coal
Mining Related Waste Streams ,
Li onitoring Sa ple'
Parameter 30 itations ~ M m
D 7-D D
- cry; ay oily `Rationale 'Frequency 1. ..Type
.. Avg. , ~ ;` Avg. ; . ..Max. ; ; . _ _.
---___-___________________~____~General Permit Requirements-------------°---------__-w-~__
Flow, MGD
Report
NA
Report
Discharge Evaluation Continuous /
Instantaneous1 Recorder /~
In-situ ~
pH, s. u. N/A NA 6.5-9.0 Water Quality Standards Weekly Grab
l s
Vi
Oil and Grease, mg/1 N/A NA 10 State Effluent Regulations Weekly sua
---
-- Federal Effluent Limitation Guidelines----------------------------

ml/1
Settleable Solids
Report
NA
0.5
Federal ELG
Weekl
Y
Grab
,
Settleable Solids, ml/1 * Report NA Report Federal ELG Weekly Grab
----------Site Specific Limitations-------------~ --g--------------__
l
i
R ____-__
Quarterl
°
Grab
Total Dissolved Solids, mg/1 ** Report NA Report ons
e u
at
Salini
i
l
l y
Monthl Grab
Total Phosphorus (as P), mg/l *** Report NA Various ons
at
Regu
Contro y
ether Pollutants of Concern Various NA Various Water Quality Standards Weekly Grab
1- For a minor facility, as determined by the EPA NPDES Permit Rating Worksheet, all weekly monitoring rega~irements shall be changed to 2 days per month.
2 - If power is eat available, flow may be measured on an instantaneous basis. Major facilities shall monitor flow weekly, minor facilities 2 days /month
3 - If a visual sheen is noticed, a grab sample muse be taken and analyzed for oil and grease
4 -Quarterly monitoring shall be prescribed if the limitation is based upon discharge to the Colorado River Basin. Ijthe limitation is based upon agricultural
protection, the monitoringfrequency shall 6e weekly.
* If caused by precipitation within any 24-hour period greater than the 10 year, 24-hour precipitation event (or snowmelt of equivalent volume)
** The TDS limitation will normally apply to discharges in the Colorado River Basin. An evaluation of the discharge will take place upon certifcation, to see if the
facility meets the 1 ton/day or 350 tons/year allowable discharge of salt. If thefacility does not meet this rega~irement, the facility will be required to submit a salinity
report documenting that achieving this level of discharge is not feasible. See Regulation 61.8(2)(1) for more information.
*** The phosphorus limitations apply to discharges to the Dillon Reservoir Wateshed, Cherry Creek Reservoir Watershed, Cha~eld Reservoir Watershed, and the
Bear Creek Watershed, as defined in Regulation 71, 72, 73 or 74 respectively. The permittee may be required to obtain a phosphorus allocation from the applicable
control regulation authority prior to certification under this general permit.
2. Alkaline Drainage Coal Preparation Plants and Coal Preparation Plant Associated Areas and Western Alkaline Coal
Minin -Tables III-a, III-b and III-c apply to Alkaline Drainage, Coal Preparation Plants and Coal Preparation Plant
Associated Areas and Western Alkaline Coal Mining. These tables cover the basic limitations, as well as alternate
limitations based upon precipitation events. These categories are subject to 40 CFR Part 434 Subparts B (Coal Preparation
Plant and Associated Areas), D (Alkaline Mine Drainage) and F (Miscellaneous Provisions). These limitations also apply tt~
Western Coal Mining Operations. Additional limitations for Western Coal Mining can be found under Section III.A.3 of this
rationale. At a minimum, the following limitations may apply as outlined in these subparts.
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