Union Gold Inc a subsidary of MW Platoro LLC

NPDES permit CO0038954 · Major NON-POTW · administratively continued, expires 2024-05-31 · EPA's file as of 2026-09-19

Check this month's numbers before you file

This permit expired on 2024-05-31 and is administratively continued: its last limits keep applying until a new permit is issued, and EPA still expects the reports.

EPA's record, 2025-09-01 to 2026-08-31

7values over a limit
0required values missing, on 0 form(s)
0of 71 forms filed late

Last period with anything received: 2026-07-31. Most often over: Manganese, dissolved [as Mn] (3), Arsenic, total recoverable (3), Iron, total recoverable (1).

Reporting

Reports are due about 28 days after each monitoring period ends (the most common figure among CO permits in EPA's filings — check your permit).

Limits in force (157)

OutfallParameterStatisticLimitMonths
002pHMINIMUM >= 6.5 SU all year
002pHMAXIMUM <= 9 SU all year
002Solids, total suspended30DA AVG <= 30 mg/L all year
002Solids, total suspendedMX 7D AV <= 45 mg/L all year
002Arsenic, total recoverable30DA AVG <= 65 ug/L all year
002Arsenic, total recoverable30DA AVG <= 22.5 ug/L all year
002Arsenic, total recoverable30DA AVG <= 53.4 ug/L all year
002Iron, total recoverable30DA AVG <= 1000 ug/L all year
002Iron, total recoverableROLL AVG <= 218 ug/L all year
002Manganese, dissolved [as Mn]30DA AVG <= 458 ug/L all year
002Manganese, dissolved [as Mn]DAILY MX <= 4738 ug/L all year
002Chromium, total recoverableDAILY MX <= 50 ug/L all year
002Chromium, total recoverableROLL AVG <= 7.5 ug/L all year
002Molybdenum, total recoverable30DA AVG report only all year
002Molybdenum, total recoverableDAILY MX report only all year
002Zinc, potentially dissolved30DA AVG <= 135 ug/L all year
002Zinc, potentially dissolvedDAILY MX <= 315 ug/L all year
002Silver, potentially dissolved30DA AVG <= .14 ug/L all year
002Silver, potentially dissolvedDAILY MX <= .81 ug/L all year
002Copper, potentially dissolved30DA AVG <= 27 ug/L all year
002Copper, potentially dissolvedDAILY MX <= 25 ug/L all year
002Cadmium, potentially dissolvd30DA AVG <= .56 ug/L all year
002Cadmium, potentially dissolvdDAILY MX <= 3.6 ug/L all year
002Chromium, trivalent, potentially dissolvd30DA AVG <= 15 ug/L all year
002Chromium, trivalent, potentially dissolvdDAILY MX <= 50 ug/L all year
002Chromium, trivalent, potentially dissolvdROLL AVG <= 2.3 ug/L all year
002Lead, potentially dissolvd30DA AVG <= 4.5 ug/L all year
002Lead, potentially dissolvdDAILY MX <= 84 ug/L all year
002Nickel, potentially dissolvd30DA AVG <= 160 ug/L all year
002Nickel, potentially dissolvdDAILY MX <= 1038 ug/L all year
002Nickel, potentially dissolvdROLL AVG <= 24 ug/L all year
002Selenium, potentially dissolvd30DA AVG report only all year
002Selenium, potentially dissolvdDAILY MX report only all year
002Uranium, potentially dissolvd30DA AVG report only all year
002Uranium, potentially dissolvdDAILY MX report only all year
002Oil and greaseINST MAX <= 10 mg/L all year
002Radium 226 + radium 228, total30DA AVG report only all year
002Uranium, total30DA AVG report only all year
002Uranium, totalDAILY MX report only all year
002Flow, in conduit or thru treatment plant30DA AVG <= .2 MGD all year
002Flow, in conduit or thru treatment plantDAILY MX report only all year
002Mercury, total [low level]30DA AVG <= .2 ug/L all year
002Sulfide-hydrogen sulfide [undissociated]30DA AVG report only all year
002Sulfide-hydrogen sulfide [undissociated]30DA AVG <= .002 mg/L all year
002Hydrocarbons, total petroleum30DA AVG report only all year
002Hydrocarbons, total petroleumDAILY MX report only all year
002Oil and grease visualINST MAX report only all year
002Static Renewal 7 Day Chronic Ceriodaphnia dubiaSINGSAMP report only all year
002Static Renewal 7 Day Chronic Ceriodaphnia dubiaMN VALUE report only all year
002Static Renewal 7 Day Chronic Ceriodaphnia dubiaMN VALUE >= 100 tox chronic all year
002Static Renewal 7 Day Chronic Pimephales promelasSINGSAMP report only all year
002Static Renewal 7 Day Chronic Pimephales promelasMN VALUE report only all year
002Static Renewal 7 Day Chronic Pimephales promelasMN VALUE >= 100 tox chronic all year
004Temperature, water deg. centigradeMX WK AV report only all year
004Temperature, water deg. centigradeDAILY MX report only all year
004pHMINIMUM >= 6.5 SU all year
004pHMAXIMUM <= 9 SU all year
004Solids, total suspended30DA AVG <= 30 mg/L all year
004Solids, total suspendedMX 7D AV <= 45 mg/L all year
004Arsenic, total recoverable30DA AVG <= 65 ug/L all year
004Arsenic, total recoverable30DA AVG <= 22.5 ug/L all year
004Arsenic, total recoverable30DA AVG <= 44.6 ug/L all year
004Iron, total recoverable30DA AVG <= 13844 ug/L all year
004Iron, total recoverableROLL AVG <= 1681 ug/L all year
004Iron, dissolved [as Fe]30DA AVG <= 3869 ug/L all year
004Manganese, dissolved [as Mn]30DA AVG <= 458 ug/L all year
004Manganese, dissolved [as Mn]DAILY MX <= 17850 ug/L all year
004Chromium, total recoverableDAILY MX <= 583 ug/L all year
004Chromium, total recoverableROLL AVG <= 88 ug/L all year
004Molybdenum, total recoverable30DA AVG report only all year
004Molybdenum, total recoverableDAILY MX report only all year
004Zinc, potentially dissolved30DA AVG <= 135 ug/L all year
004Zinc, potentially dissolvedDAILY MX <= 315 ug/L all year
004Silver, potentially dissolved30DA AVG <= .18 ug/L all year
004Silver, potentially dissolved30DA AVG <= .042 ug/L all year
004Silver, potentially dissolvedDAILY MX <= .81 ug/L all year
004Copper, potentially dissolved30DA AVG <= 22 ug/L all year
004Copper, potentially dissolvedDAILY MX <= 25 ug/L all year
004Cadmium, potentially dissolvd30DA AVG <= .56 ug/L all year
004Cadmium, potentially dissolvdDAILY MX <= 3.6 ug/L all year
004Chromium, trivalent, potentially dissolvd30DA AVG <= 242 ug/L all year
004Chromium, trivalent, potentially dissolvdDAILY MX <= 583 ug/L all year
004Chromium, trivalent, potentially dissolvdROLL AVG <= 88 ug/L all year
004Lead, potentially dissolvd30DA AVG <= 4.5 ug/L all year
004Lead, potentially dissolvdDAILY MX <= 84 ug/L all year
004Nickel, potentially dissolvd30DA AVG <= 160 ug/L all year
004Nickel, potentially dissolvdDAILY MX <= 1038 ug/L all year
004Nickel, potentially dissolvdROLL AVG <= 24 ug/L all year
004Selenium, potentially dissolvd30DA AVG report only all year
004Selenium, potentially dissolvdDAILY MX report only all year
004Uranium, potentially dissolvd30DA AVG report only all year
004Uranium, potentially dissolvdDAILY MX report only all year
004Oil and greaseINST MAX <= 10 mg/L all year
004Radium 226 + radium 228, total30DA AVG report only all year
004Uranium, total30DA AVG report only all year
004Uranium, totalDAILY MX report only all year
004Flow, in conduit or thru treatment plant30DA AVG <= .288 MGD all year
004Flow, in conduit or thru treatment plantDAILY MX report only all year
004Sulfide-hydrogen sulfide [undissociated]30DA AVG <= .032 mg/L all year
004Mercury, total [as Hg]30DA AVG <= .18 ug/L all year
004Sulfate30DA AVG report only all year
004SulfateDAILY MX report only all year
004Hydrocarbons, total petroleum30DA AVG report only all year
004Hydrocarbons, total petroleumDAILY MX report only all year
004Oil and grease visualINST MAX report only all year
004LC50 Static Renewal 48Hr Acute Daphnia magnaMN VALUE >= 100 % all year
004LC50 Static Renewal 96Hr Acute Pimephales promelasMN VALUE >= 100 % all year
005pHMINIMUM report only all year
005pHMAXIMUM report only all year
005Arsenic, total recoverable30DA AVG report only all year
005Arsenic, total recoverableDAILY MX report only all year
005Iron, total recoverable30DA AVG report only all year
005Iron, total recoverableDAILY MX report only all year
005Zinc, potentially dissolved30DA AVG report only all year
005Zinc, potentially dissolvedDAILY MX report only all year
005Silver, potentially dissolved30DA AVG report only all year
005Silver, potentially dissolvedDAILY MX report only all year
005Arsenic, potentially dissolved30DA AVG report only all year
005Arsenic, potentially dissolvedDAILY MX report only all year
005Cadmium, potentially dissolvd30DA AVG report only all year
005Cadmium, potentially dissolvdDAILY MX report only all year
005Chromium, trivalent, potentially dissolvd30DA AVG report only all year
005Chromium, trivalent, potentially dissolvdDAILY MX report only all year
005Lead, potentially dissolvd30DA AVG report only all year
005Lead, potentially dissolvdDAILY MX report only all year
005Nickel, potentially dissolvd30DA AVG report only all year
005Nickel, potentially dissolvdDAILY MX report only all year
005Chromium, trivalent total recoverable30DA AVG report only all year
005Chromium, trivalent total recoverableDAILY MX report only all year
005Mercury, total [as Hg]30DA AVG report only all year
005Mercury, total [as Hg]DAILY MX report only all year
006pHMINIMUM report only all year
006pHMAXIMUM report only all year
006Arsenic, total recoverable30DA AVG report only all year
006Arsenic, total recoverableDAILY MX report only all year
006Iron, total recoverable30DA AVG report only all year
006Iron, total recoverableDAILY MX report only all year
006Zinc, potentially dissolved30DA AVG report only all year
006Zinc, potentially dissolvedDAILY MX report only all year
006Silver, potentially dissolved30DA AVG report only all year
006Silver, potentially dissolvedDAILY MX report only all year
006Arsenic, potentially dissolved30DA AVG report only all year
006Arsenic, potentially dissolvedDAILY MX report only all year
006Cadmium, potentially dissolvd30DA AVG report only all year
006Cadmium, potentially dissolvdDAILY MX report only all year
006Chromium, trivalent, potentially dissolvd30DA AVG report only all year
006Chromium, trivalent, potentially dissolvdDAILY MX report only all year
006Lead, potentially dissolvd30DA AVG report only all year
006Lead, potentially dissolvdDAILY MX report only all year
006Nickel, potentially dissolvd30DA AVG report only all year
006Nickel, potentially dissolvdDAILY MX report only all year
006Chromium, trivalent total recoverable30DA AVG report only all year
006Chromium, trivalent total recoverableDAILY MX report only all year
006Mercury, total [as Hg]30DA AVG report only all year
006Mercury, total [as Hg]DAILY MX report only all year
UST1Temperature, water deg. centigradeMX WK AV report only all year
UST1Temperature, water deg. centigradeDAILY MX report only all year

Built from EPA's ECHO bulk files. EPA's file, not the permit document, is the source: read your permit. Check a report before you file it · All states