To preserve and restore the ecological function of Sequalitchew Creek and Edmond Marsh through habitat improvement and flow restoration.
Partner with citizens and regional stakeholders to enhance the watershed
and all that’s within it.
We oppose dewatering the Vashon Aquifer at the South Parcel mine expansion site because of the permanent, negative and adverse effects on Sequalitchew Creek, Edmond Marsh and the nearshore, freshwater springs along DuPont’s shoreline at the Puget Sound.
What is dewatering and why do we oppose it? If the mining were to expand into the South Parcel, according to Cal Portland draining of the Vashon Aquifer is required because the aggregate exists within the water table. The Vashon Aquifer is a regional aquifer within the Central Pierce Sole Source Aquifer.
Dewatering will cause permanent, irreversible damage to Edmond Marsh which is part of our public supply drinking water system. According to the city of DuPont’s Water System Comprehensive Plan, Edmond Marsh is connected to the Vashon Aquifer and falls within our Wellhead Protection Area.
Our drinking water supply in DuPont is dependent on groundwater and surface water recharge. Dewatering will drop the groundwater table 18″ or more at Edmond Marsh, which is a 139 acre Class I Wetland. Several of the wells monitoring the toxic TCE plume from the JBLM Logistics Center will need to be replaced if dewatering occurs.
Cal Portland’s own consultants confirm that if dewatering occurs at the South Parcel, nearby Sequalitchew Creek water levels will drop to zero, permanently.
The freshwater, nearshore seeps along DuPont’s shoreline at the Puget Sound will be severely degraded, permanently, if dewatering occurs. ESA-listed salmon from nearby Nisqually River and the forage fish they feed on depend on this fresh water to live. Sequalitchew Creek and DuPont’s shoreline lies within the newly created Nisqually Reach Aquatic Reserve.
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