HYDRO29057

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

(Public Notice Description)
/r should also be noted that the Division is ax~are that some ojthe discussion items under this Facility Description section
represent earlier stages. The Division does plan to upda[e this discussion after receipt oJpublic notice cornrnents
C. Wastewater Treatment Facility Description:
1. Wastewater Treatment Svstem: The wastewater treatment svstern that x~ll be utilized at BMR/ includes: an
enhanced evaporation system that would result in no direct discharge !o the Rito Seco during the period of the year
when this is feasible to use; and during the other times ojthe year when a direct discharge to the Rito Seco would
occur, the jollox~ng processes x~ote[d be utilized: a water softening system, nvo lined mining/softening ponds, o
rnernbrarte separation/nanofiltration system, and n.~o sludge holding ponds. These processes have been used in the
existing interim rater treatment system, and xill also be used as part of the final (permanent) water treatment system
which has been constructed and is scheduled to be operational by March or April 20G1q. The trearrnen[ facililty has
been designed to prirnarity reduce levels of manganese, suljate, and fluoride.
Previously, for an initial evaluation, BMR/ conducted a pilot treatment test on the backfill water to determine the
efficiency ojrtanofiltration on the sulfate, manganese, and fluoride concentrations. The pilot study test results are
included in 7R-26, Appendir C. The long-term inter management plan described in TR-26 identified nanofiltra[ion as
the likely treatment option.
Flow Measurement: During the operation ojthe permanent San Luis rater treatment plant, rater flow data will be
gathered at a number of locations. Flow totalizers wi([ be placed in the discharge pipe from the plant, in the
discharge pipes located at each pond xit/tin the system, in the reverse osmosis concentrate line, and in the bleed
water line. /n addition to these devices, Jlow totalizers are presently located on each ajthe backf~l! wells and on
the alluvial curtain x~ells. Data xi[l be gathered from each ojt/tese paints on a daily basis and cataloged an the
production report jar the previous 24 hour period. The data gathered from these points will be used to determine
the Jlox~ balances x~thin the system as well as the quantities of water discharged from each position.
Monthly Reported Existing
Concentrations NOV/CDO No. of
Avg/Min-Max Trigger Levels Trigger
Parameter (3aday Average Level
Nov Dec Jan Feb /Daily Excursions
(2-1 - 2-ts) Maximum)
Flow, gpm 159/150270 55.6/120-160 309/450-545 160/380-545 Repon/Repon N/A
pH, s. u. 6.23 • / 6.8 / 6.60 / 7.29 /
5.8•-6.2• 6.3•-7.2 5.9+-7.3 7.01-7.56 6.5-9.0 Nane•
Total Arsenic, mg/1 0.00066 / <0.001 / <0.001 / <0.001 /
<0.001-0.002 <0.001 <0.001 <0.001 0.05 /Report None
Po[. Dis. Cadmium, mg/1 <0.0001 / <0.0001 / <0.0001 / <0.0001 /
<0.0001 <0.0001 <0.0001 <O.Q001 0.0008 / 0.002 None
Dis. Copper, mg/I 0.00033 / <0.001 / <0.001 / <0.001 /
<0.001-0.001 <0.001 <0.001 <0.001 Report /Report N/A
WAD Cyanide, mg/I <0.01 / <0.01 / <0.01 / <0.01 /
<0.01 <0.01 <0.01 <0.01 Report /Report N/A
Fluoride, mg/1 1.88 / 1.4 / 1.23 / 1.15 /
0.68 - 3.51 LOS - 2.09 0.66 - 2.03 <0.5 - 2.36 Report /Report N/A
Dissolved Iron, mg/I 0.006 / 0.003? / 0.011 / <0.01 /
<0.01-0.02 <0.01-0.01 <0.01-0.026 <0.01 0.30/Report None
Pot. Dis. Lead, mg/1 <0.001 / <0.001 / <0.001 / <0.001 /
<0.001 <0.001 <0.001 <0.001 0.002 / 0.047 None
Dissolved Manganese, mg/I 0.0116 / <0.1 / 0.00675 / <0.01 /
<0.01-0.035 <0.01 <0.01-0.027 <0.01 0.05 /Report None
Total Mercury, mg/I <0.0001 / <0.0001 / <0.0001 I <0.0001 /
<0.0001 <0.0001 <0.0001 <0.0001 0.00001 /Report None
Pot. Dis. NicAel, mg/1 <0.001 / <0.001 / <0.001 / <0.001 /
<0.001 <0.001 <0.001 <0.001 0.068 / 0.659 None
Tot. Recov. Selenium, mg/I <0.001 / <0.001 / <0.001 / <0.001 /
<0.001 <0.001 <0.001 <0.001 Report / 0.01 None
Sulfate, mg/1 7.5 40 111 34
1.5 - 13.3 30 - 57 24 - 190 3.2 - 55.6 250 /Report None
Pot. Dis. Silver, mg/I <0.0002 / <O.U002 / <0.0002 / <0.0002 /
<0.0002 <0.0002 <0.0002 <0.0002 0.00003 / 0.0009 None