Passage Data · Check a report · Use it from your AI

Dominion Energy South Carolina, Inc.

Electric Services, major discharger, Walterboro, South Carolina. NPDES permit SC0002020 expired Mar 31, 2022; its limits still apply. Last 12 months: no values over a limit. Source: EPA ECHO, Oct 22, 2026.

Reports due
About 29 days after each period: outfall 004 form 1 monthly (12 values), outfall 004 form 2 quarterly (2 values), outfall 006 form 1 monthly (10 values), outfall 006 form 2 quarterly (2 values), outfall 004 form 3 yearly, outfall 006 form 3 yearly
Last report on file
September 2026
Oct 2024 – Sep 2025
0 values over a limit, 0 required values missing, 0 of 34 reports late

Limits in force (32)

ParameterStatisticLimitMonthsOutfall
pHinstantaneous minimum≥ 6 SUall year004
pHinstantaneous maximum≤ 8.5 SUall year004
Solids, total suspendedmonthly average≤ 30 mg/Lall year004
Solids, total suspendeddaily maximum≤ 100 mg/Lall year004
Oil & Greasemonthly average≤ 15 mg/Lall year004
Oil & Greasedaily maximum≤ 20 mg/Lall year004
Floating solids, waste or visible foam-visualdaily maximum≤ 0 N=0;Y=1all year004
Flow, in conduit or thru treatment plantmonthly averagereport only (MGD)all year004
Flow, in conduit or thru treatment plantdaily maximumreport only (MGD)all year004
Number of Eventsmonthly averagereport only (#)all year004
Mercury, total [as Hg]monthly averagereport only (ng/L)all year004
Mercury, total [as Hg]daily maximumreport only (ng/L)all year004
Duration of dischargedaily maximumreport only (hr)all year004
Oil and grease visualdaily maximum≤ 0 N=0;Y=1all year004
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiamonthly average≤ 25 %all year004
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiadaily maximum≤ 40 %all year004
Pass/Fail Static 48Hr Acute Ceriodaphnia dubiadaily maximum≤ 0 pass=0;fail=1all year004
pHinstantaneous minimum≥ 6 SUall year006
pHinstantaneous maximum≤ 8.5 SUall year006
Solids, total suspendedmonthly average≤ 30 mg/Lall year006
Solids, total suspendeddaily maximum≤ 100 mg/Lall year006
Oil & Greasemonthly average≤ 15 mg/Lall year006
Oil & Greasedaily maximum≤ 20 mg/Lall year006
Floating solids, waste or visible foam-visualdaily maximum≤ 0 N=0;Y=1all year006
Flow, in conduit or thru treatment plantmonthly averagereport only (MGD)all year006
Flow, in conduit or thru treatment plantdaily maximumreport only (MGD)all year006
Mercury, total [as Hg]monthly averagereport only (ng/L)all year006
Mercury, total [as Hg]daily maximumreport only (ng/L)all year006
Oil and grease visualdaily maximum≤ 0 N=0;Y=1all year006
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiamonthly average≤ 25 %all year006
%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiadaily maximum≤ 40 %all year006
Pass/Fail Static 48Hr Acute Ceriodaphnia dubiadaily maximum≤ 0 pass=0;fail=1all year006

How strict are these limits?

Cited limits by parameter: South Carolina's rules and the federal ones.

Same industry: the 17 Electric Services permits in South Carolina.

Check this month's numbers Email me before each report is due

· Save this facility as a site · Superfund sites nearby · Your permits on one board

On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/SC0002020 · MCP: https://passage-data.com/mcp