State of Oregon Department of Environmental Quality

Summary of Changes to 1200-A Permit Requirements

Category Old 1200-A New 1200-A

Best 

Management 

Practices

Implement best management practices (BMPs) that are 

appropriate for the site and describe the BMPs in a 

Stormwater Pollution Control Plan (SWPCP).

Added mandatory BMP requirements (for example, “erosion and sediment control, spill 

prevention response”). Additional erosion and sediment control requirements (for example, 

preventing sediment trackout).

Water Quality 

Based Effluent 

Limits

Do not cause a violation of in-stream water quality 

standards.

Do not cause or contribute to a violation of instream water quality standards.

Uncommingled mine dewatering water from certain categories of facilities are subject to 

numeric effluent limits.

Benchmarks

Meet statewide stormwater discharge concentration 

benchmarks total suspended solids, settleable solids, pH 

and oil and grease.

Meet lower TSS benchmarks. 

Facilities subject to numeric effluent limits for TSS or pH are not also subject to benchmarks.

Other 

Pollutants

Facilities that discharge to impaired waters for sediment 

or turbidity have the option to sample their discharge 

based on a turbidity value of 160 NTU or implement 

additional BMPs.

Added permit eligibility requirements for new discharges to impaired waters without water 

quality restoration plans. 

Removed the turbidity monitoring option.

Impairment 

Pollutants

No requirement

Facilities discharging to waters impaired for the following pollutants, but for which there is 

not a total maximum daily load (TMDL), must monitor twice per year for these pollutants:

New facilities discharging into waters impaired with any of the above pollutants must 

prevent any exposure to the pollutant in their discharge, document in the facility’s SWPCP 

that the pollutant is not present at the site, or provide information to DEQ or Agent that their 

discharge would not cause or contribute to a water quality standards violation.

New facilities discharging to a water that has a TMDL must comply with the requirements of 

the TMDL, if any exists 

Aldrin Heptachlor

Arsenic Iron

Arsenic (tri) Lead

Chlordane Mercury

Copper PCBs (Concrete Batch Plants only)

DDT Temperature (mine dewatering only)

DDT Metabolite (DDE) Zinc

Dieldrin
Category Old 1200-A New 1200-A

Benchmark 

Exceedances

Within 30 days of receiving water quality sample results 

that exceed a benchmark concentration, submit Action 

Plan that contains (1) results of review, (2) a corrective 

action, (3) and an implementation schedule.

Complete Tier I corrective actions are required when stormwater sample results exceed 

benchmark or impairment reference concentrations. Tier I requirements are similar to 

responses in the old permit, except only submit to DEQ or Agent changes made to SWPCP 

based on investigation. Retain Tier I corrective action report on site and submit to DEQ or 

Agent upon request.

Tier II corrective actions are required if a second-year geometric mean concentration exceeds 

a benchmark. Must implement treatment BMPs within two years. Professional engineer or 

certified engineering geologist must design and stamp the portion of the SWPCP addressing 

the treatment measures.

Sampling Sample 4 times per year.

Samples must be collected at least 14 days apart.

Added requirement to monitor during first 12 hours of a stormwater discharge event (This 

does not apply to discharges of mine dewatering water).

Monitoring 

Waiver

Monitoring waiver can be obtained for individual 

parameters after four consecutive samples collected are 

at or below the benchmark or exceedance due to 

background or natural conditions.

Monitoring waiver can be obtained for individual parameters after four consecutive samples 

are at or below the benchmarks or reference concentrations based on geometric mean 

evaluation or due to background natural conditions. 

Waivers are not available for numeric effluent limits.

Inspections

Regular inspections of diversion ditches, seepage ponds 

and receiving waters during operation. 

Monthly inspections of areas where potential spills of 

significant materials or industrial activities occur, and 

where stormwater control measures, structures, catch 

basins, and treatment facilities are located. 

Added daily inspections of active clearing, grading and excavation areas when stormwater 

discharge is occurring. 

Reduced inspection requirements for unstaffed or inactive sites to every three months during 

the rainy season. 

Added that permit holders must document inspection results in a report and retain it on site