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Talking aggregate with Eric Mears - AZ Mining Review #45

America’s infrastructure is built of sand, gravel, and crushed rock; collectively referred to as aggregate. And that is the topic of our 45th episode of the Arizona Mining Review - an interview with Eric Mears on gravel production and consumption in the Phoenix Metro area.

Aggregate is a primary ingredient in manufacturing concrete used to construct roads, bridges, airports, utilities, buildings, homes, and all other types of infrastructure. According to the US Geological Survey’s 2018 Mineral Commodity report (1), aggregate production in the U.S. topped $23 billion in 2017, falling just south of the $26.3 billion for all U.S. metal mine production.

One sunny morning in the final week of April 2018, Eric Mears, Vice President at Haley & Aldrich, Inc., joined our video team on a river terrace overlooking the Agua Fria River in Surprise, Arizona, to talk aggregate. Eric has nearly 30 years of experience in environmental and water resources services for the industrial mining industry.

Arizona Mining Review #45: Aggregate - the building blocks of Arizona 

River systems naturally concentrate aggregate, filtering and washing sand and gravel particles before depositing them on the channel floor or across adjacent floodplains.

The Phoenix metro area, with 4.7 million people, has a prodigious appetite for sand and gravel. Rule of thumb: aggregate consumption in the U.S. is approximately 10 metric tons per individual per year (2). In Phoenix, that appetite is satisfied by harvesting sand and gravel from stream beds of the Agua Fria River, New River, Salt River, Gila River and the Hassayampa River.

The aggregate resource map for the Phoenix Metro area, 'Geologic Map Database for Aggregate Resource Assessment in the Phoenix Metropolitan Area and Surrounding Regions, Arizona' can be downloaded. It includes a report, map graphic, the GIS database.

Eric and the team at Haley & Aldrich, Inc., advise mining firms in mineral assessment and environmental-friendly strategies for quarrying aggregate. In this 8-minute video, Eric describes the significance, rationale and challenges of mining aggregate from sites juxtapositioned between developing and established communities.   

Last, the annual production value of sand & gravel in Arizona is second only to copper. And Arizona was second only to Nevada in the value of nonfuel mineral production – which includes aggregate -  in the U.S. Arizona trails California, Texas, Minnesota, and Michigan in aggregate production.

Note: Eric has served on the Arizona Geological Survey’s Geologic Mapping Advisory Committee since 2011.

  1. Source US Geological Survey Mineral Commodity Report 2018 (
  2. Source: Rocks and (