Construction Stormwater General Permit Appeals
2015 Construction Stormwater General Permit Appeal and Modification
On November 18, 2015, Ecology issued an updated Construction Stormwater
General Permit (CSWGP). The permit became effective January 1, 2016. One appeal
was filed with the Washington Pollution Control Hearings Board (PCHB) on
December 17, 2015 and a settlement agreement was reached for a minor permit modification.
- Washington Aggregate and Concrete Association
- Associated General Contractors of Washington
- Inland Northwest Associated General Contractors
- Associated Builders & Contractors Western Washington Chapter
- Associated Builders & Contractors Inland Pacific Chapter
- Building Industry Association of Washington
Final permit with modifications (effective May 5, 2017)
Final permit with modifications - Redline
Changes to the permit
CSWGP Settlement Agreement
Appeal Dismissal Order
Fact Sheet for the CSWGP modification
Fact Sheet Addendum for the Draft Permit Modification - Response to Comments
Economic Impact Analysis (2015)
Final changes to the CSWGP
The proposed changes are to dust control (S1.C.3.i), pH sampling requirements (S4.D), engineering calculation requirements (S9.B.1.f), and concrete washout (S9.D.9.h). The proposed changes are found in the proposed CSWGP modification – redline version and listed below. Changes are marked using strikeouts and underlines (new language).
- S1.C.3.i - Uncontaminated or potable water used to control dust. Permittees must minimize the amount of dust control water used.
- S4.D - pH Sampling Requirements – Significant Concrete Work or Engineered Soils
If construction activity results in the disturbance of 1 acre or more,
and involves significant concrete work (significant concrete work means greater than 1000 cubic yards poured concrete
or recycled concrete used over the life of a project ) or the use of
recycled concrete or engineered soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD], or fly ash), and stormwater from the affected area drains to surface waters of the State or to a storm sewer system that drains to surface waters of the State, the Permittee must conduct pH sampling as set forth below. Note: In addition, discharges to segments of water bodies on Washington State’s 303(d) list (Category 5) for high pH are subject to a numeric effluent limit for pH; refer to Special Condition S8.
- For sites with significant concrete work, the Permittee must begin the pH sampling period when the concrete is first poured and exposed to precipitation, and continue weekly throughout and after the concrete pour and curing period, until stormwater pH is in the range of 6.5 to 8.5 (su).
- For sites with recycled concrete where monitoring is required, the Permittee must begin the weekly pH sampling period when the recycled concrete is first exposed to precipitation and must continue until the recycled concrete is fully stabilized
and stormwater pH is in the range of 6.5 to 8.5 (su).
- S9.B.1.f – Engineering calculations for ponds, treatment systems, and any other designed structures.
When a treatment system requires engineering calculations, these calculations must be included in the SWPPP. Engineering calculations do not need to be included in the SWPPP for treatment systems that do not require such calculations.
- S9.D.9.h - Assure that washout of concrete trucks is performed off-site or in designated concrete washout areas only. Do not wash out concrete truck
drums or concrete handling equipment onto the ground, or into storm drains, open ditches, streets, or streams. Do not dump excess concrete on site, except in designated concrete washout areas. Concrete spillage or concrete discharge
directly to groundwater or to surface waters of the State is prohibited.
Do not wash out to formed areas awaiting LID facilities.
- Appendix A – Definitions – Significant Concrete Work means greater than 1,000 cubic yards poured concrete
or recycled concrete used over the life of a project.
- Table 3: Summary of Primary Monitoring Requirements – Footnote 2
2 If construction activity results in the disturbance of 1 acre or more, and involves significant concrete work (1,000 cubic yards of poured
concrete or recycled concrete over the life of a project) or the use of
recycled concrete or engineered soils (soil amendments including but not limited to Portland cement-treated base [CTB], cement kiln dust [CKD], or fly ash), and stormwater from the affected area drains to surface waters of the State or to a storm sewer stormwater collection system that drains to other surface waters of the State, the Permittee must conduct pH sampling in accordance with Special Condition S4.D.
In addition to the proposed changes to the CSWGP, Ecology agreed to provide
the following guidance for Low Impact Development (LID) facilities and which offsite areas are to be included in the total disturbed acreage.
Protection of Low Impact Development (LID) facilities under Special Condition S9.D.13.
- LID BMPs may be used to manage construction stormwater during construction; however, LID BMPs that will be used post construction (permanent facilities) must be restored to fully functioning condition. This includes, if necessary, the removal of sediment and replacing the removed soils with soils meeting the design specification. In addition, infiltration rates must be maintained or restored to meet post construction LID design criteria.
Coverage of offsite areas under Special Condition S1.B.1.a.
- The determination of total disturbed acreage for the purposes of permit coverage must include off-site acreage that will be disturbed as a direct result of the construction project and will discharge stormwater. For example, off-site equipment staging yards, material storage areas, borrow areas, and parking areas as indicated in S1.C.2. Off-site acreage does not have to be included for the purposes of determining total acreage disturbed if it is covered under a separate permit coverage for any stormwater discharge.
Written comments on the draft permit modification and fact sheet were accepted from December 21, 2016 to February 10, 2017.
We received the following comments:
We will review the comments and we expect to issue a final permit modification and response to comments on March 22, 2017
with an effective date of May 5, 2017.
Workshop and Public Hearing
We held a workshop and public hearing on the draft permit modification as an online webinar on
February 6, 2017.
The workshop explained the proposed modification to the permit. Please contact Amy Moon (360-407-6467 or
firstname.lastname@example.org) if you have any questions.
2005 Construction Stormwater General Permit Appeal
Four parties appealed the construction stormwater general
permit (issued November 16, 2005).
The Pollution Control Hearings Board issued a final decision.
You may read the conclusion here:
Findings of Fact, Conclusions of Law and Order, PCHB No. 05-157, 158, and 159
Download copies of the appeals:
Copyright © Washington State Department of Ecology. See http://www.ecy.wa.gov/copyright.htm