Page 67 - 2022 Sustainability Report

ENVIRONMENTAL STEWARDSHIP

specialized equipment is used to treat and recirculate aggregate wash water in a nearly closed-loop system. This
significantly reduced the volume of water appropriated for gravel washing. The addition of the plate press also allowed us
to recover additional water while converting “pond fines” (small rock particles suspended in water) into a co-product
generated from the process.

Our Texas ready mix operations undertook initiatives designed to reduce water waste. In particular, all but one of our
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North Texas plants have installed Shumaker Industries “Load and Go Ready Mix Truck Wash” systems. These systems
dramatically reduce the amount of water used to clean ready mix trucks after loading, reducing both water use and
runoff.

The West Division continues to work in cooperation with the City of Denver, the City of Aurora and the State of Colorado
to create much-needed new fresh water reservoirs at our facilities. These water projects include on-going projects at our
Riverbend Sand & Gravel, 35th Avenue, Taft Sand & Gravel, Specification Aggregates, Duckworth, and Heaton facilities
with the opportunity to repurpose more pits in the future. The West Division is also working to develop storage facilities in
other locations within its footprint to serve various communities.

Our Colorado Front Range operations are situated adjacent to rivers, streams and ditches that provide vital water for
agricultural, residential and commercial purposes. This system of water distribution through streams and ditches was
established in the 1880’s supplying water from the Mountains to the Front Range below. Through our numerous water
rights, 4 state approved reservoirs and leases, Martin Marietta operates to ensure there is no net water loss to the stream
system. This means that our total water usage is returned back monthly to the stream system and the surrounding
aquifers. In 2022, Martin Marietta returned over 400 million gallons of water back to the environment through this
process.

While water conservation and protection is key in our western operations, it is not neglected elsewhere. For example, our
East Division has spent almost $6 million dollars in the past four years on clarifier and other water system upgrades to
ensure both process water recovery and stream protection. The most recent projects were undertaken at the division’s
Kent Sand and gravel site in Maryland, its Arrowood Quarry in North Carolina and its St. Mary’s Sand site in southern
Georgia.

Our Medina Rock & Rail water recovery pond
Hondo, Texas

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