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\~ ~. ^; Y 11 Ir ~,., ". ,f ir~ ENEC~4 co,NCom~~r ~~~ 2 ~ 2006 Seneca Coa! Company i D'm•ron a MicwrreU •nd GedWY July 24, 2006 Colorado Department of Health WQCD-PE-B2 4300 Cherry Creek Drive South Denver, CO 80246-1530 RE; Quarterly Discharge Monitoring Report £or Permit CO-0000221 Dear Sir or Madam: Pursuant to the quarterly reporting requirements contained in Colorado Discharge Permit CO-0000221 for the Seneca Mine Complex, enclosed find the second quarter 2006 discharge monitoring reports for Points 002 to 006 and 008 to 017. Intermittent discharges were observed at Points 005, 013 and 014. Construction of Pond 014 was completed in September 2001, and first began discharging this quarter. Due to winter snow, vehicle access to Points 004, 008, 009, 015, 016 and 017 was closed until May. Monthly visits in April were performed by snowmobile, all-terrain vehicle or on foot. Five excursions of effluent limits occurred this quarter. A sample collected on June 7 at Point 003 had a total suspended solids (TSS) value of 36 mg/1. The effluent limits are 35 mg/1 (monthly average) and 70 mg/1 (daily max.). It is suspected that this high value is related to a bloom of algae noted at the time of sampling. The point was flowing at a rate of 15 gpm at the time of the excursion. At the receiving stream, Grassy Creek, 400 feet below the discharge point, a TSS value of 18 mg/1 was measured, with a flow value of 611 gpm. The TSS value at Point 003 was 16 mg/1 in July, indicating that the excursion was transitory and that the discharge point is now in compliance. The second excursion occurred at Point 005. A sample collected on April 13 had a TSS value of 50 mg/1. The effluent limits are 35 mg/1 {monthly average) and 70 mg/1 (daily max.). A retest of the sample, performed beyond the holding time, had a value of only 20 mg/1. The sample was collected during snowmelt runoff, and therefore, an alternate of the TSS limit ("report") is allowed for in our permit (Part I.A.1, pg. 5). A picture of the site at the time of the excursion, indicating that snow was still on the ground, is attached. The third and fourth excursions occurred at Point 014. A sample collected on April 12 had a TSS value of 170 mg/1. The effluent limits are 35 mg/1 (monthly average) and 70 mg/1 (daily max.). The same sample had a total iron value of 6.31 mg/l. The effluent limits are 3 mg/1 (monthly average) and 6 mg/1 (daily max.). The sample was collected during snowmelt runoff, and therefore, an alternate of the Seneca Coal Company • P,O. Box 670 • Hayden, Colorado 81639 Telephone (970) 276-3707 • FAX (970) 276-3014