Hanson Turns Concrete Gray Water Green

Hanson Aggregates West Region was facing a welcome population boom around its San Diego base, but thanks to restrictive zoning laws, maintaining plants’ environmental integrity was challenging.

The challenge was to produce maximum yardage with minimal space, while maintaining Hanson’s environmental compliance and stewardship. Yet, the small yard area necessitated constant water cleanup, frequent dredging, and minimal sludge drying time. And, there never seemed to be an end to shoveling and hauling the cement paste.

When Hanson Aggregates West Region Area Managers walked the aisles of the World of Concrete, they visited a booth featuring an ALAR Auto-Vac® Water Recycling System.

Months later, a pilot unit was rented and tested at the Oceanside facility. The Auto-Vac® was put to the test by processing a slipstream of concrete slurry water that measured around 200,000 ppm TSS. The result was crystal clean, 1/2-micron filtrate water that measured less than 25 ppm TSS. The dry solid material came off the filter at about 30 percent moisture content by weight. The trial was a success, and a full-scale system was ordered.

Hanson’s problems of real estate, yard water clean-up, and hauling costs were solved.

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