East End Wastewater Treatment Facility Saves With New Equipment


By Carol McCracken  (Post # 1,534)

The East End Wastewater Treatment Facility on Munjoy Hill has announced it has generated over $200,000 in savings annually.  This comes from new equipment and process changes installed in the recent past.

The Portland Water District’s four wastewater treatment plants clean roughly 8 billion gallons of wastewater a year which results in nearly 20,000 tons of organic material being transported offsite.  Maximizing the processing of this material improves the efficiency of the plant, lessens odors, reduces costs and benefits the environment.

Biosolids, which are the organics in wastewater, are removed through a process called dewatering.  They are then loaded into tractor trailer dump trucks and transported to a landfill or compost facility.

In 2010 and 2011, the District’s loads were averaging around 25-26 tons per load.  Improvements in dewatering processes and a focus on maximizing truck loading, has raised that average to 29 tons fo reach load in 2012.

Recent improvements in dewatering processes included the addition of a liquid polymer, adjustments to the gravity belt thickner and new rotary presses.  All these improvements have resulted in $5 drier biosolids which are easier to load and transport  Because biosolids are transported an average of 100 miles away, fuller trailers reduce the number of trips needed.

Precision is important as overfilling containers can be messy and dangerous.  New ultrasonic sensors and fabricated equipment which disperses material more evenly from chutes has helped operators add more material to each trailer. Recently installed cameras and weight logs have also aided to gauge weekly success and sustain improvement, according to a press release issued by Michelle Clements Public Relations Manager for the Portland Water District.

The increase in load weights in 2012 alone reduced the number of truckloads 11%, from 806 in 2010 to 719.  In May of 2013, the average was over 29 tons per load and the plants are on track to reduce truckloads below the 700 mark for the year.

“We are very pleased as this effort produces positive results for the environment and helps to fulfill our goal to maximize operational efficiencies,” stated Director of Wastewater Scott Firmin.  “Our operators have really stepped up to this challenge and we could not have achieved these results without the support of our partner in biosolids management, Casella Organics.”

For more information, please email mclements@pwd.org