Demand for gravel leads to conflict in Pierce County city where mine expansion proposed

A proposed mining expansion in the city of DuPont has generated some concern with its potential environmental impacts, including the draining of local groundwater that feeds into a creek along the popular Sequalitchew Trail .

Walkers on the trail earlier this month could hear the shallow trickle of Sequalitchew Creek mumbling through a green canopy of trees bearded with moss. Some residents worry that trickle would disappear and the surrounding wilderness would die if mining up the hill is allowed to expand and continue.

The mining company argues it has a plan to restore the creek and says it wants to expand because demand for gravel has increased dramatically with population growth.

The Pioneer Aggregates South Parcel Project would expand current sand and gravel mining operations in southwestern Pierce County in previously undisturbed areas, according to a city fact sheet about the project. CalPortland ’s mining operations at the Pioneer Aggregates Mine could expand 188 acres across and 125 acres deep into a portion of the existing mine. If given the green light, the project would extend mining operations there for about 14 years.

It wouldn’t come without impacts to the environment.

The proposal would result in the logging of about 15 acres of coniferous trees, eliminate the previously undisturbed 10.8-acre Kettle Wetland, clear about 60 acres of shrublands and grasslands and remove about 90 landmark trees, among other impacts, according to a draft environmental impact statement (EIS) prepared by the city. Landmark trees typically require protection due to their rareness, size, age, structure or ecological condition.

In addition, wells would be installed to intercept and pump groundwater out to dry gravels for mining, according to the draft EIS.

“The intercepted groundwater would be conveyed by surface channels and infiltrated in ponds on the floor of the Existing Mine,” the city said in the draft EIS.

Barb Kincaid is DuPont’s community development director and the policy official for the environmental impact process. Kincaid told The News Tribune in an email Friday that the city received over 300 public comments “voicing many concerns about the adverse environmental impacts from this proposal” during the 30-day comment period. Those comments are being categorized and discussed internally, which may take two to three weeks, she said.

The next step for the city is to finalize and issue a final EIS with a recommendation to DuPont’s hearing examiner, who makes the final decision on whether the project will move forward, Kincaid said. If the permit isn’t approved, the denial could be appealed to Superior Court, she said.

To mine or not to mine?

CalPortland wants to expand mining operations to extract an additional 30-40 million tons of sand and gravel, according to the draft EIS. Based on past market demand, about 2.8 million cubic yards of material would be extracted each year for 14 years.

The mine is in the northern end of the city at 4301 Pioneer Ave.

Mining and later reclamation of the site are “intended to serve as a final remedy for any lead and arsenic impacted soils” associated with past industrial activities on the site from the DuPont Dynamite Co. and the Asarco Co. copper smelter plume , according to an impact summary in the draft EIS. If the project is not approved, the land would remain forest and future developers would have to deal with site contamination.

A mining expansion would result in a decrease in the Vashon Aquifer levels, which is expected to impact groundwater within a two-mile radius of the site. Drinking-water supplies in Sequalitchew Springs, DuPont’s Bell Hill and Hoffman Hill wetlands are not expected to be impacted by the project, according to the draft EIS.

The expansion also would result in habitat loss for many mammals, birds and amphibians near and within the site, according to the draft EIS. If approved, up to 79% of the groundwater flows to Sequalitchew Creek would be lost. Water temperatures would fall in the winter and rise in the summer, and habitat and fish migratory patterns would also be disrupted, according to the draft EIS.

A restoration plan for the Sequalitchew Creek , to be funded by CalPortland if the mining expansion progresses, would restore habitat and increase creek flow from Sequalitchew Lake through Edmond Marsh into Sequalitchew Creek canyon, according to the draft EIS.

In a 2011 settlement agreement between CalPortland Company, the city of DuPont, the Washington Department of Ecology and other environmental stakeholders, CalPortland agreed to restore the creek, maintain the shorelands of Puget Sound and fund the permitting process and restoration work to do so. If the mining expansion project isn’t approved, the city would have to find alternative funding to restore the Sequalitchew Creek, according to the draft EIS.

If the proposal to expand operations is rejected, mining would continue in its existing capacity above groundwater levels, or the site would be developed in a different way under its existing zoning. According to the draft EIS, the existing mine has an estimated remaining lifespan of six to 10 years.

Need for gravel

CalPortland has operated at the Pioneer Aggregates Mine since 1997 and “is the largest building materials company producing cement and construction materials products in the western United States,” according to its website . It operates 17 mines in Washington, in addition to 17 in Oregon, two in Alaska, one in Vancouver, B.C. and more in California, Nevada and Arizona, according to a map on its website.

The company applied for permits to mine the north parcel in 2013 and applied for permits to mine the south parcel in 2021, which is the expansion project.

Pete Stoltz, senior manager of permitting and government affairs for the company, told The News Tribune on Wednesday he knows some people aren’t thrilled about the mining project but said increased mining here addresses a greater need in the Puget Sound region and beyond.

Stoltz said the quality of rock mined at the DuPont site is strong and clean, which results in stronger concrete that lasts longer. That means builders don’t need to use as much rebar to strengthen the concrete when building or release as much carbon dioxide when making the concrete in the first place, Stoltz said.

The facility’s unique location on Puget Sound means CalPortland can transport material by barge as opposed to trucks, he said. The company is a major producer of materials needed for construction and remediation projects throughout the metropolitan region, and gravel is a limited resource, Stoltz said.

“Demand for gravel is directly correlated to population. Our population has increased dramatically and the demand for gravel increased dramatically, and [cities] haven’t really planned for it,” he said. “That’s one of the reasons that this resource is very important and access[ing] it with the existing facilities that we have. We’ve looked pretty hard to find another deposit similar somewhere that we could access, and we just haven’t found it.”

Stoltz argues mining is an interim land use. He points to Chambers Bay golf course and Butchart Gardens in Victoria, the site of a former limestone quarry, as examples of mined areas that have been transformed into new places for public use.

“There’s mines that have been used for agricultural land, forestry, developed property. And, you know, with modern reclamation practices, we can do a really good job,” he said.

‘I can’t even imagine all of this being gone’

On a walk alongside Sequalitchew Creek on Aug. 15, DuPont residents Krista Novak and Judy Norris said they’ve been outspoken against the mining project, concerned about the environmental impacts and changes it could bring to an area where they find refuge.

“I can’t even imagine all of this being gone,” Norris said, gesturing to the trees and ferns along the trail. “It’s just so beautiful.”

Thinking about the aquifer being drained and the vegetation drying up as a result of more mining fills her with grief and anger, Norris said. As the climate changes, DuPont has been seeing higher temperatures, and she worries about the risk of fire in the creek valley.

“It’s greed,” Norris said. “I do understand that the state wants gravel. We need infrastructure, we need roads, but there are a lot of gravel mines around here.”

Novak said she moved to DuPont for the beautiful trails and green space and projects like the expansion would have significant community impact.

“It’s our job as citizens to protect our land and our water and our air and the noise pollution and the vegetation and the animals. It would change quite a bit what people in the community love,” she said. “We don’t know if it’s inevitable that it will happen, but if it is, the plan needs to become a better plan and consider more things than just the immediate property the mine is on.”

Resident Robin Barrow is concerned mining would harm the endangered western gray squirrel species that is only found in this area west of the Cascades. Barrow said she doesn’t trust CalPortland to fully restore the area and argues the destruction additional mining could bring would never truly be remediated.

“Once it’s gone, it never comes back … Think about the generations that will be affected by that. What if they needed that water from the aquifer at some point in wells for future development, for homes, for people?” she said. “As long as I’m there [in DuPont], I want to protect it as much as I can. Our future demands it.”