2011-01-24_REPORT - C1980005

• Permit No: C1980005
• IBM Index Class Name: REPORT
• Doc Date: 1/24/2011
• Doc Name: 2009 AHR Review Response
• From: Seneca Coal Company
• To: DRMS
• Annual Report Year: 2009
• Permit Index Doc Type: Hydrology Report
• Email Name: SLB
• Email Name: SB1
• Media Type: D
• Archive: No

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Seneca Coal Company Water Quality Assessment CO-0000221
Table A-5
In-stream Standards for Stream Segment COUCYA13E
Physical and Biological
Dissolved Oxygen DO = 5 mg/l, minimum
H=6.5-9su
Fecal Coliform = 2000 colonies/ 100 ml
Inorganic
Un-ionized ammonia acute = TVS
Un-ionized ammonia chronic = 0.06 Mg/1
Chlorine acute = 0.019 mg/1
Chlorine chronic= 0.011 mg/1
Free Cyanide acute = 0.005 mg/1
Sulfide chronic = 0.002 mg/1
Boron chronic = 0.75 mg/1
Nitrite = 0.05 mg/1
Metals
Total Recoverable Arsenic acute = 100 u 1
Dissolved Cadmium acute and chronic = TVS
Dissolved Trivalent Chromium acute and chronic = TVS
Dissolved Hexavalent Chromium acute and chronic = TVS
Dissolved Copper acute and chronic = TVS
Total Recoverable Iron chronic= 1000 u 1
Dissolved Lead acute and chronic = TVS
Dissolved Manganese acute and chronic = TVS
Total Mercury chronic = 0.01 u 1
Dissolved Nickel acute and chronic = TVS
Dissolved Selenium acute and chronic = TVS
Dissolved Silver acute and chronic = TVS
Dissolved Zinc acute and chronic = TVS
Standards for metals are generally shown in the regulations as Table Value Standards (TVS), and
these often must be derived from equations that depend on the receiving stream hardness or species
of fish present. The Classification and Numeric Standards documents for each basin include a
specification for appropriate hardness values to be used. Specifically, the regulations state that:
The hardness values used in calculating the appropriate metal standard should be based
on the lower 95% confidence limit of the mean hardness value at the periodic low flow
criteria as determined from a regression analysis of site-specific data.
Where insufficient site-specific data exists to define the mean hardness value at the
periodic low flow criteria, representative regional data shall be used to perform the
regression analysis. Where a regression analysis is not appropriate, a site-specific
method should be used.
Hardness data for the mainstems of Sage Creek and Grassy Creek, and the tributaries to Dry Creek,
Sage Creek, Fish Creek and Grassy Creek near the points of discharge from the Seneca Coal
Company were unavailable. Hardness data were available for the mainstem of Fish Creek, but were
Appendix A Page 7 of 19 Last Revised 8/30/06 AN