1815 13TH ST SEPA 016 - 013 - PRMC NEW CLINIC BUILDING Land Use Decision Documents 2025-04-21

PUBL/C WORKS*77- MEMORANDUM TO: Gordon Witcher, Patrick Hansen -Lund (MKA), Jane Zimmerman FROM: Dave Voigt DATE: May 3, 2013 SUBJECT: PRMCE Utility Plant Expanded Parking Facility, Stormwater Ponds Meeting Notes for May 1, 2013, attendees: Dave Voigt, Pat Hansen -Lund (MKA), Mike Gaffney (PRMCE). 1) Reviewed various information from the Storm Drainage Design Report. This document has also been reviewed by Jane Zimmerman and is consistent with Everett SWMM. The basis of design for the ponds appears to satisfy the requirements of the Interim Policy on Stormwater Control #2- 11. 2) Discussed some design details associated with the flow restrictor structure: suggested eliminating the 3 small diameter high-level overflow pipes and lowering the top pipe opening (overflow) to an elevation that would preclude a surcharge from the SD collection system inlets. Also consider enlarging the restrictor orifice diameter to reduce maintenance (due to clogging) and to allow added flow to be received into the ponds from the CUP site. Also consider relocating the structure to be closer to the paved parking lot so a vactor truck can reach the manhole access for cleaning. 3) Dave Voigt wishes to implement a change to the facility that introduces the storm water runoff from the existing CUP site parking lot area which is currently un-detained. It appears that one new saddle manhole structure and approximately 100 LF of pipe (probably 18" dia.) and various pipe appurtenances would accomplish that flow diversion. An approximate budget cost for design and construction is $50K. The intent is to furnish some degree of runoff detention for both sites which would reduce the peak flows downstream in the City system — in particular at the 17'' St interceptor. There was general agreement that the concept is workable. 4) Mike G. emphasized that PRMCE does not have any available budget to help pay for any extra work and that the project needs to begin as soon as possible while funding is available. Two issues may cause the City to withdraw its request to add CUP runoff to the pond facility: a) Existing UG fuel storage tanks may be obstacles to trenching and pipe installation to connect the CUP SD system to the west pond. Patrick agreed to investigate this. b) The City needs to verify that there is a workable mechanism for the City to compensate PRMCE for engineering and construction and that the cost is acceptable/reasonable. Paul McKee needs to help resolve this issue.