12.23.2014  |  News

Summary of Washington’s NEW Industrial Stormwater General Permit


The new Washington Industrial Stormwater General Permit (Permit) has arrived, effective January 2, 2015! The permit is generally similar to the 2010 permit. Though the permit includes some potentially problematic new provisions, Ecology has backed off on several impactful changes that were proposed in the draft permit based on public comments received.

Stormwater Pollution Prevention Plans

  • All Stormwater Pollution Prevention Plans (SWPPPs) must comply with the new permit by 01/30/2015 (Section S4.c). All inspection reports must now be included with the SWPPP. Additionally, SWPPPs need to be brought into alignment with the updated Stormwater Management Manual (SWMM) applicable for each permittees region and/or jurisdiction.
  • Stormwater drainage and treatment facilities must be maintained in accordance with the most recent Washington Stormwater Management Manuals (Section S3.B.4.b.i.3.b). For the 2012 Stormwater Management Manual for Western Washington, click HERE. For the 2004 Stormwater Management Manual for Eastern Washington, click HERE.
  • We advise that facilities look at the new Permit and the applicable Stormwater Management Manual and write the SWPPP as if it were for the first time.


  • Consistent attainment of benchmarks may be based on samples collected during the 2010-2014 permit cycle. Once consistent attainment is (or was) met, sampling may be suspended for one or more parameters for a period of three years (12 quarters) (Section S4.B.6). It’s not clearly stated in the permit, but Ecology inspectors have described that the three-year clock should be considered to start (or have started) when the facility achieved consistent attainment. For example, if your facility achieved consistent attainment at the end of 2012 then you will need to start sampling again beginning in the first quarter of 2016.
  • A petroleum hydrocarbons benchmark of10 mg/L (NWTPH-Dx) has been included for Transportation Facilities and Petroleum Bulk Stations and Terminals (S5.B Table 3).
  • Changes to sampling locations, discharge points, and/or outfalls must be recorded and submitted to Ecology on an updated form (Section S4.B.2.d). A copy of this form can be found HERE.
  • Weather conditions must be recorded when a sample is collected (Section S4.B.3.h).
  • If multiple samples are collected over a 24-hr period, results must be averaged and the daily average used when calculating the quarterly average (S4.B.6.c).
  • Ecology’s databases have been found inaccurate in some instances. Permittees should visit the PARIS database, check the accuracy of your data and send a certified letter to Ecology requesting that the database be corrected if needed.

Discharges to Impaired Waters

Ecology had proposed several additional changes to this section S6 in the draft permit that were not carried forward to the final 2015 final permit based on comments received during the public review process.

The most significant changes to this section of the permit surround discharges to 303(d) listed water bodies and Puget Sound Sediment Cleanup Sites (PSSCSs). PSSCSs are defined in document provided on Ecology’s website; and permittees that want to know whether they drain to a 303(d) listed water body should go to the following website to find out: http://www.ecy.wa.gov/programs/wq/303d/currentassessmt.html

There are several requirements for discharges to each of these categories; some apply to both, some individually. We’ve attempted to clarify who needs to do what, but it can be very complicated and special conditions abound. We encourage each permittee to really understand the areas that they drain to and what rules apply. The information below pertains to existing dischargers.

Hopefully this helps:

  1. Discharges that were subject to effluent limits (including TSS) under the 2010 permit will continue to have the applicable effluent limits.
  2. Discharges to 303(d) listed waterbodies impaired due to sediment (that were not identified in the 2010 permit) will have a TSS effluent limit that will go into effect on 01/01/2017.
  3. Discharges to PSSCSs will have a benchmark for TSS that will go into effect on 01/01/2017. TSS benchmark sampling will also be subject to permit provisions regarding substantially identical outfalls, averaging, corrective actions, etc. If a facility currently has a benchmark for TSS, the new benchmark will supersede.
  4. Both 2 and 3 will need to sample for TSS and report data to Ecology beginning 01/02/2015.
  5. Discharges to PSSCSs (including Category 5 dischargers) are subject to storm drain line cleaning BMPs, solids sampling, and reporting at least once prior to 10/1/ 2016 (Section S6.C.2.d). Our advice is to start line cleaning efforts early. Doing this work can be complicated and time-consuming depending on the availability of maps, the complexity of drainage systems, inaccessible of CBs, etc. Folks may want to clean their lines early to get rid of potential legacy pollutants (since many drainage systems haven’t been cleaned since the good old days, if ever). Then sample closer to the deadline to collect samples representative of current operations.
  6. Make sure to check if your facility should be on the list in Appendix 4. Ecology’s discharge locations can be incorrect and it is the permittees’ responsibility to know if their discharge is subject to permit conditions. You won’t get a break just because you’re not on the list if you should be. At the same time, if you shouldn’t be on the list, request by certified letter for Ecology to remove your facility.


  • Discharge Monitoring Reports and other written reports must be submitted electronically (Water Quality Permitting Portal), unless a waiver is granted (Section S9.3).
  • Written reports of non-compliance must be submitted within 5 days (rather than 30 days under existing permit), but may be waived on a case-by-case basis, if phone notification occurs within 24 hours (Section S9.E.c).

Corrective Actions

  • Before installing engineered structures, permit holders shall submit an engineering report, plans and specifications, and an Operation and Maintenance Plan. The 2015 permit Engineering Report requirements are reduced from those required under the 2010 permit (Section S8.D.3.a).
  • Clarifying language has been provided regarding Level 2 and 3 Corrective Actions. While a time extension is in effect, benchmark exceedances (for the same parameter) do not count towards additional Level 2 or 3 Corrective Actions (Section S8.C.4.d).

KJ has the experience and know-how to interpret the permit and determine how it applies to your facility. We have found that permit language is often difficult to decipher and some interpretation (and sometimes creativity) is required to see how the permit applies to each particular situation. We have advocated our clients’ interests since the permit was first issued in 1993, with the goal of achieving and maintaining compliance while minimizing impacts to your facility.

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