Initiatives in the field

Saving water saves money

For over 40 years, United Rock Products has been operating a large underwater gravel pit at Irwindale, California on the outskirts of Los Angeles, The sand and gravel are dredged, screened, crushed and washed. The water used to wash the sand and gravel is recycled after clarification in a series of settling ponds.

But in 2006, the company had to find another way to recycle this water since the only sand and gravel remaining to be extracted was located underneath the settling ponds, which of course could no longer be used. A new system including a classifier, sand augers, a hydro-cyclone and a settling tank was installed. The resulting sludge is then sent to a filter press. 

Over $1M was invested in the new recycling system, but this is less than what it used to cost to maintain the settling ponds for three years. In this part of California, where water is a precious commodity, the reduction in consumption that this new system provided entitles the company to the reimbursement of its unused water allocation. For fiscal 2008-2009 this represented a check of almost $300,000. According to Russ Caruso, the company's VP and General Manager: "It's clear that we are saving money, but recycling water is also important for the environment and the community. This project was absolutely necessary." Indeed, this was a win-win-win project that:

  • Extended the quarry's life
  • Reduced operating costs
  • Reduced water consumption
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Ken Barker