HomeMy WebLinkAboutLetter to J. Ding re Request for SEPA Addendum 4862-4626-5193 v
June 13, 2023
Via Email (jding@rentonwa.gov)
Jill Ding, Senior Planner
City of Renton CED
Planning Division
1055 S. Grady Way, 6th Floor
Renton, WA 98057
Re: Sounders FC Center at Longacres – Request for SEPA Addendum re Cork Infill Selection
Dear Ms. Ding:
We are pleased to let you know that the Seattle Sounders FC organization has made a
determination that it will now use cork infill for the synthetic turf fields at Sounders FC Center
at Longacres. This is a significant environmental commitment by the Sounders to avoid using
SBR crumb rubber infill, which was under consideration and studied as the likely fill material.
As you know, Conditions 1.c and 1.d of the Hearing Examiner’s Conditional Use Permit
Decision incorporated a SEPA condition imposing water quality monitoring requirements for
many years, and mandating a second environmental review to include those monitoring results
when infill was to be replaced (following approximately five years of use). The stated condition
also required the applicant to increase the size of the Bioscape water quality treatment system
for the fields to a 2-year storm size, which exceeds what is required by applicable stormwater
regulations. The basis for all of these requirements was the prospective use of SBR crumb
rubber, a common form of synthetic field infill that was under consideration at the time. The
concern was that SBR crumb rubber can include the constituent 6PPD-Q, which may be toxic
to salmonids if it enters fish-bearing water bodies.
The contaminant 6PPD-Q is not implicated with the use of cork infill materials. Please
see the attached memorandum by Herrera Environmental Consultants, Inc., which addresses
the safety of using cork infill for synthetic playfields, and its conformity to Washington State
water quality standards. The water quality monitoring is not required by any applicable water
quality regulation, and this expensive mitigation measure is unnecessary in the absence of SBR
crumb rubber infill. The requirement to upsize the treatment facility also is inapplicable with
the commitment to use cork infill instead of SBR crumb rubber. Please see the attached letter
and sizing analysis provided by CPL, the Sounders’ civil engineer responsible for stormwater
management, which proposes to adjust the size of the Bioscape facility consistent with
applicable regulations.
Jill Ding, Senior Planner
June 13, 2023
Page 2 of 2
Based upon the determination not to use SBR crumb rubber infill, the Sounders ask
that the City confirm (1) that water quality monitoring specified in Condition 1.c and repeat
environmental review specified in Condition 1.d are not required if the Project does not use
SBR crumb rubber, and (2) if cork infill is used for the synthetic turf fields, then the Bioscape
treatment system may be sized consistent with applicable regulations rather than for the 2-year
storm, as demonstrated by CPL. In essence, the shift to cork infill provides equal or better
environmental mitigation for the synthetic fields than would be accomplished by performing
the condition as written.
We understand that a SEPA addendum may be required for this request. An
addendum may be used at any time during the SEPA process. WAC 197-11-706. Please let us
know if you need anything additional from the applicant in that regard.
Very truly yours,
Ann M. Gygi
Ann M. Gygi
Attachment
AMG:vjh
E-Mail: ann.gygi@hcmp.com
Direct Dial: (206) 470-7638
cc: Tom Chiado
Maya Mendoza-Exstrom
Julia Reeve
Jeremy Eckert
ND: 22873.003 4862-4626-5193v3