HomeMy WebLinkAbout001H. R. ESVELT ENGINEERING
Environmental Engineering
January 4, 2010
Ref: Pleasant Harbor Marina and Golf Resort
Wastewater Reclamation Plant EIS Process Description
Sub: Response to County Staff, Peer Review Team and public input Comments
From: H. Richard Esvelt, P.E.
PDF 1-2 and 1-3 Draft Technical Reports -- County Staff Comments dated 9/22/09
Page 13 A & B. — corrections made.
PDF 2 — Bill Persich Comments on the Wastewater Reclamation Plant Process (WRP)
Description
Page 1 Table A — WRP Design Data: (l. Notes added following Table A)
Comments bI, b2 and b3 — Annual Average Flow does not reflect equivalent residential unit (ERU)
flow contribution, but is an average of the monthly flows shown below in the list. The ERU unit
flows and loadings are reflected in the High Season Average (June thru Sept), which is the only
season of the year when full occupancy is project. Seasonal occupancy was estimated by project
planners.
Based upon a High Season Average flow of 0.18 mgd is 210 gallons per day per ERU, which at 2.5
PE per ERU is 84 gpd per PE. The High Season Average loading of 450 lbs BOD & TSS per day is
0.52 Ib BOD & TSS per day per ERU, which at 2.5 PE per ERU is 0.2 lb BOD & TSS per PE.
WRP process and system design is based upon the Maximum 3 -day Equalized Weekend flows and
loadings.
Page 11 Table B — Chlorine System Feed concentration (1. Change made)
Comment b5 — (no comment on b4) — I agree, I will take this up with WDOH. It should also read
`design', not `minimum'.
Page 12 Table B — Sludge Dewatering (1. appropriate — final report, change made)
Comment b6 — `Thickener' should have read `Dewatering Feed Pump'
Page 13 3.1.B. Irrigation with treated effluent that does not meet Class A Reclaimed Water
Requirements (1. appropriate — final report, change added)
Comment V — irrigation will be by drip irrigation of landscaped areas or subsurface percolation
system.
6450 N.E. Brigham Rd., Bainbridge Island, WA 98110 206-842-7988 PAX 206-780-0811
SEIS Scoping Comments
Page 5 — Pharmaceuticals and hormones present in recycled wastewater should be removed. (3. Will
not be included in the revised report).
To date, as far as the author knows and I read the relevant periodicals, there currently is no means to
remove these components from wastewater and no regulatory agency has approached the question
(though there is a great deal of interest in the subject). These components do break down over time.
First, to answer other comments, treated wastewater will NOT be injected into the aquifer after
treatment and the nutrient nitrogen will be removed to meet drinking water requirements. Treated
and disinfected wastewater will be used to irrigate golf course grasses and for fire control in natural
areas around the course, where a portion of these noted components will be taken up by the grass
and natural vegetation. The cut grass will likely be composted to add further breakdown of the
grass. Any wastewater that percolates through the soil will be further treated with the biological
mix in the soil matrix, which could be a removal mechanism for pharmaceuticals and hormones
present in wastewater.
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