PERMFILE105530

• Permit No: C1982056
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 44 NPDES Permit No. CO-0042161
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENV/RONMENT, Water Quality Control Division
Rationale -Page 2, Permit No. CO-0042161
~II.FACILITY DESCRIPTION
A. Industry Description
Ty0e o(Industry: This facility is an underground coal mine in a continuous state ojdevelopment/expansion.
Mining utilizes the "longwall"method of coal extraction. Production is specified by the permirree as 10 million
tons of coal per year.
Chemicals Used: The permiltee indicated that seven chemicals are used to treat waters and may be in the
e~'luent discharges. These chemicals are summarized in the table below. The table shows whether the Division
finds the chemicals acceptable for discharge at concentrations appropriate for the purposes intended..
Table III-I -Chemicals
Chemical Name Purpose Outfall Acceptable/Unacceptable
NaOH pH elevation 00! acceptable
H2SO4 pH reduction 001 acceptable
En-Act 7883 settling 001 acceptable
En-Act 8873 settling 001 acceptable
En-Chem 9015 sea/ing/floccularion 001 acceptable
Aqua Ward disinfection/chloriwtion 002 acceptable
B. Wastewater Treatment Description
• The wastewater treatment system has not changed since the previous permit.
Three treatment cells are used in combination to treat underground mine drainage. The system is not designed nor
used fo treat surface water runoff: The permittee adds chemical jlocculants and coagulants as necessary (see
III.A.3.above). The discharge from this pond is outfal1001, which goes to Fish Creek The mine sump is pumped once
every five to seven days, typically, with one pump moving 500 to 550 gpm jot 18 to 36 hours resulting in 30-day
average flows oj0.76 MGD. The jacility has the capability to use two pumps in parallel resulting in a capacity of
1100 gpm (daily maximum flow = 1.58 MGD).
In 1992, the permittee constructed a domestic wastewater treatment jacility (WWTF) to replace a failing septic system.
The new R'WTF consists offour Lined aerated lagoons with chlorine disinfection. Discharge from this jacility goes to
the edge of a previously backfilled area where it mixes with spoils spring water from the Emerald Springs spoils
spring. The designated discharge point jot outfall 002 is defined as the e,/Jluent weir in the control building, prior to
entering the spoils spring. The combined spoils spring water is used within the mine for dust suppression. A portion of
this water is then taken up in the produced coal, the remainder drains to a sump that is pumped to the industrial pond
and discharged through outfall 001.
Pursuant to the authority of Article 9, Title 25, Regulations for the Certification of Water Trerument Plant and
Wastewater Treatmem Plant Operators, every water treatment facility, domestic or industrial wastewater treatment
facility shall be under the supervision of a terrified operator holding a certification in a class equal to or higher than
the class of the jacility. The Operator Certification Board is within the Colorado Department of Public Health and
Environment and should be comacted at [phone] for any questions relative to specific requirements.
~V.PERFORMANCE HISTORY
A. Monitoring Data
I. Discharge Monitoring Repots: Tabfes /V-I and /V-2 summarize the effluent data and Table TV-3 summarizes
the influem data reported on the quarterly Discharge Monitoring Reports (DMR's) for the Twenrymile Coal