HYDRO29057

• Permit No: M1988112
• IBM Index Class Name: Hydrology
• Doc Name: TABLE OF CONTENTS
• Media Type: D
• Archive: No

COLORADO DEPARTMENT OF HEALTH, Water Qualih~ Control Division
Rationale -Page 6 Permit No. CO-0045675
V. PERFORMANCE H/STORY
A. Monitoring Data
Discharge Monitoring RepoKs and Self-Monitored Reporting Data.• Since this is a new permit, no routine discharge
monitoring reports have been submitted yet. However, BMR/ has commenced treatment of the contaminated
groundwater in the West Pit and disclutrge this treated x•ater under the terms of the Amendment No. 1 to the Notice of
Viola«on and Cease and Desist Order (NOV/CDO), which was issued on Oc[ober 8, 1999. This Ametuiment to Ute
NOV/CDO requires that biweekly reports of the discharge be submitted m the Division. Discharge from the system
and initiation of the two-week start up period began on October 13, 1999. Daily effluent sample collections were
ini«ated at this time with those sample collections being analyzed jot the following parameters: pH, Jlow, sulfate,
dissolved manganese, and fluoride. Since the initial tune of startup, treated discharge samples lurve been collected on
a weekly basis and analyzed for the jolloxang parameters as indicated in Table V-1. There were two ezceedances of
pH laboratory analytical trigger levels during installation and startup; however, field pH readings tivere in compliance
xith the pH trigger levels. These apparent laboratory ezceedances are indicated in the footnotes * and d below which
follow Table V-/. As indicated in the following table during the period after the initial start-up period, no ezceedances
of die trigger levels established in the NOV/CDO hm•e occurred. The Mgger levels are equal to the x~ater gtmliN
standards for segment 28. Table V-! includes a summary ojthe reported discharge data from /0.13-1999 through 7-
18-2000.
Table V-/ -- Self-Monitoring Results

Cons«tuent Number
of
Effluent
Samples Mean EjJluent
Concertina«on
(ng/l) Range of
Effluent
Concentrations
(rag/l) Existing
NOV/CDO
Trigger Levels
(30-Day Average
/DailyMazimurn) Number aj
Ezceedances
of the Monthly
Average
Effluent
Trigger Level Number of
Erceedances
of «te Daily
Marimum
Effluent
Trigger Level
Tonal Arsenic 35 0.00217 <0.001-0.019 0.05 /Report 0 N/A
Por. Dis. Cadmium 35 0.0000002 <0.001-0.0001 0.0008 / 0.002 0 0
Dissolved Copper 35 0.00051 <0.001-0.006 Report /Report N/A N/A
WAD Cyanide 35 <0.01 <0.01 Report /Report N/A N/A
F[uonde 46 1.13456 <0.5-3.83 Report /Report N/A N/A
Dissolvedlron 35 0.01768 <0.01-0.094 0.30 /Report 0 N/A
Potentially Dis. Ixad 34 0.000428 <0.001-0.013 0.002 / 0.047 0 0
Dissolved Manganese 46 0.01295 <0.01-0.089 0.05 /Report 0 N/A
Total Mercury 35 <0.0001 <0.0001 0.00001 / Repott 0 N/A
Pat. Dis. Nickel 35 0.00017 <0.001-0.006 0.068 / 0.659 0 0
Tor. Recov. Selenium 35 0.00031 <0.001-0.005 Report / 0.01 N/A 0
Sulfate 46 85.96739 I.5-374. I 250 /Report 0 N/A
Potentially Dis. Silver 35 <0.0002 <0.0002 0.00003 / 0.0009 0 0
Poreruially Dis. Zinc 35 0.00185 <0.005-0.012 0.073 / 0.08 0 0
Flow, gpm 120 - 545 Report /Report N/A N/A
pH (s. u.) 46 Median 7.0 5.5-8.14*tt 6.5 - 9.0 N/A 0
< = less than Po[. Dis. means die potentially dissolved fraction, as de, fined in the Basic Standards mui
Methodologies (or Surface Water (Regulation No. 3/).
* The range of efJtuem pH measurements includes all awlvtical laboratory reported pH values during the penod October 13,1999 to
July 18, 2000. Prior to January 16, 2000, the reposed pH value was as determined by the analytical laboratory and were subject to
potential analytical bias associated xedt carbon dioxide jonnation and pH reduction during transport and smrage. Since that date al[
reported arwlvtical pH values have been field measuremems to eliminate the carbon dioxide bias in accordance x~«t EPA policy and
guidance. Although the reported analytical pH value during the penod October 13, 1999 through January 16, 2000 was biased by the
carbon dioxide interference, field pH measurements have been collected for the entire period October 73, 7999 through July 18, 2000 and
at no «rne has the effluent discharge field pH measuremem fallen outside the Daily Maximum trigger level range of 6.5 to 9.0.
q /nitially, flee reported laboratory pH values whie/e were below t/re 6.5 s. u. Mgger level were 5.8 (/1-/999). 6.2 p/-99), 6.3 1/2-1999).
and 5.9 s. u. (1-2000). This occurred during and irnrrtedia[e[y followng the initial start up period (October 1999) for the treatment
system. A!! field pH values that have been reported have been greater titan 6.5 s. u. The rx~o field measured pH values for January 2000
x•ere 6.98 oral 7.3 s. u. Also, field pH data at the doxvtstream stations RS-2 and RS-5 were well in cornpliartce xith the pH smndard (RS-2
values were 7.95 s. u. [0 8.5 s.u.during 10-1999 through /-20'00; and RS-5 pH values ranged from 8.05 to 8.4 s. u. during 10-1999 through
1-20'00). Stttce the «me just after the initial start up penod for the treatment system (November 1999 through July 2000). all pH values in
the discharge have been in compliance xLh the pH trigger level range.