PC419_Craig_Riley_11-16-2018From:Craig Riley
To:Lori Barlow
Subject:Painted Hills Planned Residential Development Project Re-Submittal; Flood Zone Management - Fill
Date:Friday, November 16, 2018 4:41:39 PM
Ms. Barlow:
I would like to provide you with a few comments regarding this proposal to manage flood plain
issues for the proposed Painted Hill PRD by using fill material for the site. Since the project is so
complex and the response time is limited, I will limit my comments and concerns to two basic areas:
Environmental impacts of the fill material: The impact of moving 400,000+ cubic yards of
topsoil at the side to bring in 330,000+ cubic yards of imported fill material and then replacing
and re-contouring the 400,000+ topsoil will be tremendous and needs to receive detailed
consideration in the formal EIS; specifically the EIS should consider in depth:
Air quality and traffic impacts of the 25,000 to 30,000 loads of fill material to be
delivered to the site
Site restoration requirements for the site(s) that will be the source of this fill material
Noise pollution impacts to the surrounding neighborhoods resulting from the
manipulation of around 1.1 million+ CY of fill material
Air quality impacts from blowing dust from handling 1.1 million+ CY of fill material
Water quantity requirements for dust control and compaction of 700,000+ CY of
material
Flood zone impacts due to filling the site:
Provide flood zone delineation, flood velocity estimates and damage due to flood
inundation and scouring on parcels neighboring the PRD site in the event the proposed
facilities are not large enough or fail and flood water are diverted around the fill
materials on to adjoining properties
Provide detailed water quality impacts due to dissolved heavy metals and organic
chemical, particularly the BTEX compounds associated with fuels that will be
discharged to the Spokane Valley-Rathdrum Prairie Aquifer in what in the past was
designated as a particularly sensitive location
Proved a detailed assessment of the water quality impacts to all public water system
sources downstream of the injection/infiltration site along with proposals for public
water systems to assure compliance with regulated and unregulated compounds under
the Safed Drinking Water Act
Consider applying water quality requirements from WAC 173-200 – Groundwater
Quality Standards to the water discharged from the injection system in lieu of relying
on bioswale treatment to produce acceptable water quality; please recall that the
Flood Control Narrative dated 8/20/18 notes that most floods in this watershed occur
during winter when the bioswale grasses are dormant and unable to provide even the
minimum chemical removals provided by viable ground cover and grasses and also
states that the water is to be “disposed” of in the gravel gallery; disposal implies the
proponent considers this wastewater and therefore should be required to comply with
state ground water quality requirements
Consider requiring the twin 48” concrete pipe transmission pipes along Madison Road
to include manholes at 300-400 foot intervals to allow maintenance and cleaning to
assure the pipes to not silt in during “normal” flood years
Consider requiring to the proponent to demonstrate the viability of the proposed
gallery system under winter conditions; typical winter conditions could like include
scenarios where early rain and snow events drain to the gravel gallery and the residual
water freezes in the gravel pores and then a major flood event occurs when a portion
or allow the gallery is unavailable to ‘dispose’ of the water.
I appreciate your consideration of these comments.
Craig Riley
3926 S Eagle Lane
Spokane Valley, WA 99206