Wastewater treatment plant leads the way

A wastewater treatment plant in Arizona has led the way internationally in how best to deal with excess levels of waste water.

The plant, in the town of Cave Creek, has not always been well received by locals for a number of reasons but it has now been rewarded by being named as one of the American Public Works Association (APWA) Projects of the Year in the Environmental category.

The facility has certainly had a fair bit of work to do in terms of rowing back for poor public perception, largely due to inadequate odour control facilities and being located in the middle of a busy neighbourhood.

However, the plant has been revamped over the past three years to include a number of features and useful tools.

So much so, that the treatment capacity of the plant now stands at 0.66 million gallons per day which represents a six-fold increase over that of the old plant.

This expanded capacity, it is reported, can help to accommodate as many as 5,000 new residential connections while it has also been instrumental in driving business to the town.

The plant has helped to attract new commercial establishments with officials saying that it can often 2.25 million gallons per day more in future.

Also included in the plant's new makeup is an influent pump station designed to lift the raw wastewater into the plant to be treated in various stages beginning with a rotary drum screen and vortex grit removal.

The next stage involves biological treatment with a sequencing batch reactor (SBR) process which consists of two treatment trains and a post-equalization basin.

Then there is a cloth disc filtration followed by disinfection with hypochlorite in a chlorine contact basin.

Any solid sewage that remains from the treatment process are then pumped from the SBR process train basins and into a sludge holding tank.

The sludge is pumped to a belt filter press before being disposed at a local landfill with odour control coming from chemical wet scrubbers.

Posted by Lauren Steadman