Transalta Centralia Generation LLC — NPDES permit WA0001546: limits, due date and EPA's record

Electric Services, major discharger, Centralia, Washington. NPDES permit WA0001546, in force until Jan 31, 2027. Last 12 months: no values over a limit, 4 of 45 reports late. Source: EPA ECHO, Oct 22, 2026.

Limits in force (78)

Parameter	Statistic	Limit	Months	Outfall
Temperature, water deg. centigrade	daily maximum	≤ 17.5 deg C	all year	001
Turbidity	daily maximum	report only (NTU) (alert, not enforceable)	all year	001
Turbidity	monthly average	report only (NTU) (alert, not enforceable)	all year	001
Oxygen, dissolved [DO]	minimum	≥ 8 mg/L	all year	001
pH	maximum	≤ 9 SU	all year	001
pH	minimum	≥ 6 SU	all year	001
Solids, total suspended	daily maximum	≤ 100 mg/L	all year	001
Solids, total suspended	monthly average	≤ 30 mg/L	all year	001
Chromium, hexavalent [as Cr]	daily maximum	≤ 18.1 ug/L	all year	001
Chromium, hexavalent [as Cr]	monthly average	≤ 10.4 ug/L	all year	001
Chromium, total [as Cr]	daily maximum	≤ .2 mg/L	all year	001
Chromium, total [as Cr]	monthly average	≤ .2 mg/L	all year	001
Copper, total [as Cu]	daily maximum	≤ 13 ug/L	all year	001
Copper, total [as Cu]	monthly average	≤ 8.9 ug/L	all year	001
Zinc, total [as Zn]	daily maximum	≤ 1 mg/L	all year	001
Zinc, total [as Zn]	monthly average	≤ 1 mg/L	all year	001
Selenium, total [as Se]	daily maximum	≤ 8.2 ug/L	all year	001
Selenium, total [as Se]	monthly average	≤ 5.6 ug/L	all year	001
Chlorine, total residual	daily maximum	≤ 50 ug/L	all year	001
Chlorine, total residual	monthly average	≤ 50 ug/L	all year	001
Chlorine, free available	daily maximum	≤ .5 mg/L	all year	001
Chlorine, free available	monthly average	≤ .2 mg/L	all year	001
Turbidity, background	daily maximum	report only (NTU) (alert, not enforceable)	all year	001
Turbidity, background	monthly average	report only (NTU) (alert, not enforceable)	all year	001
Mercury, total [as Hg]	daily maximum	≤ 20 ng/L	all year	001
Mercury, total [as Hg]	monthly average	≤ 10 ng/L	all year	001
Flow	daily maximum	≤ 12.12 MGD	all year	001
Flow	monthly average	≤ 6.36 MGD	all year	001
Oil and grease visual	maximum	≤ 0 N=0;Y=1	all year	001
BOD, 5-day, 20 deg. C	monthly average	≤ 30 mg/L	all year	002
BOD, 5-day, 20 deg. C	weekly average	≤ 45 mg/L	all year	002
BOD, 5-day, 20 deg. C	monthly average	≤ 9 lb/d	all year	002
BOD, 5-day, 20 deg. C	weekly average	≤ 13.5 lb/d	all year	002
pH	maximum	≤ 9 SU	all year	002
pH	minimum	≥ 6 SU	all year	002
Solids, total suspended	monthly average	≤ 30 mg/L	all year	002
Solids, total suspended	weekly average	≤ 45 mg/L	all year	002
Solids, total suspended	monthly average	≤ 9 lb/d	all year	002
Solids, total suspended	weekly average	≤ 13.5 lb/d	all year	002
Chlorine, total residual	daily maximum	≤ 1 mg/L	all year	002
Chlorine, total residual	monthly average	≤ 1 mg/L	all year	002
Coliform, fecal general	monthly average	≤ 200 #/100mL	all year	002
Coliform, fecal general	weekly average	≤ 400 #/100mL	all year	002
Flow	daily maximum	report only (MGD) (alert, not enforceable)	all year	002
Flow	monthly average	report only (MGD) (alert, not enforceable)	all year	002
Nitrogen, nitrate total [as N]	daily maximum	≤ 4 mg/L	all year	FGD
Nitrogen, nitrate total [as N]	monthly average	≤ 3 mg/L	all year	FGD
Arsenic, total [as As]	daily maximum	≤ 18 ug/L	all year	FGD
Arsenic, total [as As]	monthly average	≤ 8 ug/L	all year	FGD
Selenium, total [as Se]	daily maximum	≤ 70 ug/L	all year	FGD
Selenium, total [as Se]	monthly average	≤ 29 ug/L	all year	FGD
Mercury, total [as Hg]	daily maximum	≤ 103 ng/L	all year	FGD
Mercury, total [as Hg]	monthly average	≤ 34 ng/L	all year	FGD
Flow	daily maximum	report only (MGD) (alert, not enforceable)	all year	FGD
Flow	monthly average	report only (MGD) (alert, not enforceable)	all year	FGD
pH	maximum	≤ 9 SU	all year	P3E
pH	minimum	≥ 6 SU	all year	P3E
Solids, total suspended	daily maximum	≤ 100 mg/L	all year	P3E
Solids, total suspended	monthly average	≤ 30 mg/L	all year	P3E
Chromium, hexavalent [as Cr]	daily maximum	≤ 18.1 ug/L	all year	P3E
Chromium, hexavalent [as Cr]	monthly average	≤ 10.4 ug/L	all year	P3E
Chromium, total [as Cr]	daily maximum	≤ .2 mg/L	all year	P3E
Chromium, total [as Cr]	monthly average	≤ .2 mg/L	all year	P3E
Copper, total [as Cu]	daily maximum	≤ 13 ug/L	all year	P3E
Copper, total [as Cu]	monthly average	≤ 8.9 ug/L	all year	P3E
Zinc, total [as Zn]	daily maximum	≤ 1 mg/L	all year	P3E
Zinc, total [as Zn]	monthly average	≤ 1 mg/L	all year	P3E
Selenium, total [as Se]	daily maximum	≤ 8.2 ug/L	all year	P3E
Selenium, total [as Se]	monthly average	≤ 5.6 ug/L	all year	P3E
Chlorine, total residual	daily maximum	≤ 50 ug/L	all year	P3E
Chlorine, total residual	monthly average	≤ 50 ug/L	all year	P3E
Chlorine, free available	daily maximum	≤ .5 mg/L	all year	P3E
Chlorine, free available	monthly average	≤ .2 mg/L	all year	P3E
Mercury, total [as Hg]	daily maximum	≤ 20 ng/L	all year	P3E
Mercury, total [as Hg]	monthly average	≤ 10 ng/L	all year	P3E
Flow	daily maximum	≤ 12.12 MGD	all year	P3E
Flow	monthly average	≤ 6.36 MGD	all year	P3E
Oil and grease visual	maximum	≤ 0 N=0;Y=1	all year	P3E

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/WA0001546 · MCP: https://passage-data.com/mcp