Frequently Asked Questions

What is the purpose of the hard rock quarry?

  • The hard rock quarry, or mine, will extract high quality volcanic rock from a 25 to 30-acre quarry. This material may be used for road bases, rip rap for shoreline and dike protection, and as landscaping rock. It will likely be used locally and along the coast from North Seattle to Marysville and Arlington.
  • Follow this link to watch a short video on the importance of quarries and the materials mined from them for everyday life.

What are the benefits to the community from the mine?

  • Heidelberg Materials Gold Bar operations already employ 10 local residents; this expansion will add approximately seven new jobs that will be open to members of the local community.
  • Sand and gravel from the existing mine have been used in local projects such as Park Place Middle School in Monroe and the Paine Field Runway Taxi Lane upgrade in Everett. Similarly, Heidelberg Materials expects quarry rock to be utilized in local construction and transportation projects.
  • Heidelberg Materials concrete supplied in the local community utilizes aggregate materials from the Gold Bar operations, such as housing foundations, sidewalks, and commercial buildings.
Photo: Seismograph used to monitor vibration levels

Seismograph used to monitor vibration levels

What are the potential impacts to the community from the mining operation and what is being done to help mitigate each of these impacts?

  • Noise and Vibration from Blasting: The operation requires drilling and intermittent blasting with explosives to access the rock, which creates the potential for both noise and vibration impacts. Heidelberg Materials has developed proven techniques to avoid and minimize impacts at other quarries where blasting occurs and will use these techniques at the Gold Bar site. These include (but aren’t limited to): exact calculations for spacing of drill holes and blasting targets to minimize the noise to the greatest extent possible; and use of seismographs to monitor vibration levels. Heidelberg Materials is open to consulting with the community and scheduling the blasts at a time that works best for them.
  • Groundwater Impacts: Heidelberg Materials will conduct operations in a manner that avoids or  minimizes potential impacts to the local aquifer. Heidelberg Materials will complete groundwater studies to understand any potential risks to the aquifer from operations. This understanding will inform the quarry design to develop best management practices that will avoid or minimize impacts to the aquifer. Heidelberg Materials has successfully implemented a groundwater monitoring program for the existing sand and gravel mine and will expand this program to include the proposed expansion area.
  • Aesthetic Impacts: The proposed hard rock quarry is strategically located behind an existing elevated land feature to reduce potential aesthetic impacts.
  • Truck Traffic: During year-round full operations, the project will add 50 to 100 truck trips per day to State Route 2. To prevent material from falling off trucks and landing on the highway, Heidelberg Materials requires that their own trucks are covered, and they encourage customers and contractors to cover their loads. If any of Heidelberg Materials trucks result in damage to other vehicles, they will cover the cost of the repair.
  • Dust and Fly Rock: The location of the project is behind an existing elevated land feature that will reduce impacts from the mining operations. Transport of the material from the quarry to the processing area has the potential to create dust which will be mitigated by best management practices (i.e. water trucks for roadways).

What is the expected length of time this mine will be in operation?

  • The new hard rock quarry is proposed to be added to the existing sand and gravel mine. The production tonnage and tonnage sold of quarry rock will likely grow every year and will be in addition to the existing sand and gravel products. Based on the amount of hard rock reserves available, Heidelberg Materials estimates the quarry will be in operation for 25 years or more.