2010-12-15_PERMIT FILE - C1980005A (5)

Home Browse Search

RULE 2.04.7 HYDROLOGY DESCRIPTION AND MONITORING PLAN INTRODUCTION In 2010, the Seneca II Mine permit boundary was significantly reduced. The new permit area now includes only the Sediment Pond 008 basin. The following subjects are addressed: - Potential Hydrologic Consequences - Water Rights - Alternative Water Supply - Monitoring Plan - Ground Water Points of Compliance Reference is made to background/backup information in Tab 7 in the original PAP. POTENTIAL HYDROLOGIC CONSEQUENCES The probable surface water impacts of the Pond 008 basin are addressed in the Tab 7 beginning on page 7-247, and conclude on page 7-254. On these pages, this basin is referred to as Bond Creek. References to NPDES 007 are to a small reclaimed sediment pond that existed in the Pond 008 basin. The most important prediction in this section is on page 7-247, 1" paragraph, where it states: "The result on this analysis, presented in Table 7-73, show that in June, the TDS (total dissolved solids) concentration of Fish Creek increases 76 mg/1, from 421 mg/1 at site 26 (now replaced by site SW-S2-11, a.k.a. SSF11) to 497 mg/1 (18% increase) below Bond Creek (at site SW-S2-13, a.k.a. SSF13). Similarly, in July, the TDS concentration of Fish Creek increases 74 mg/1, from 533 mg/1 at site 26 to 607 mg/l (14% increase) below Bond Creek." The items in parenthesis in the statement above were added now to provide clarity. Locations to the sites mentioned above may be found on the map insert on the lower left part of Exhibit 7-2, Hydrology Location Map. Pond 008 discharges into Bond Creek which flows into Fish Creek. Site SSF11 (SW-S2-11 on the map) is the upstream sample site on Fish Creek above its confluence with Bond and Cow Camp Creeks. Site SSF13 (SW-S2-13 on the map) is the downstream sample site on Fish Creek below the confluence with Bond and Cow Camp Creeks. Monitoring data from 1987 to 2009 indicates that in May, the average TDS at site SSF11 was 296 mg/l, and was 322 mg/l at site SSF13, for an increase of 28 mg/l (9% increase). In June, the average TDS at site SSF11 was 485 mg/l, and was 510 mg/1 at site SSF13, for an increase of 25 mg/l (5% increase). In July, the average TDS at site SSF11 was 605 mg/l, and was 595 mg/1 at site SSF13, for a decrease of 10 mg/1(2% decrease)! These monitoring data indicate that Pond 008 (together with Pond 004, formerly with the Seneca II Mine, now part of the Peabody Sage Creek Mine) have very little impact on the water quality of Fish Creek. The monitoring data also indicates that impacts are below PHC predictions, and therefore, the PHC need not be revised. Impacts to the ground water system are discussed in below in the Ground Water Points of Compliance section. PR-02 2.04.7-1 rev. 9/10