Plant Supervisor’s Request Prompts Screening System Development

Santa Barbara is a crown jewel along California’s beautiful coast line, with lush rolling hills, luxury resorts, a historic Mission and spectacular sandy beaches. Keeping the city clean is a tall order, and the folks at the city’s El Estero Wastewater Treatment Plant take the job very seriously.

The design includes a shaftless auger as the lifting screw to prevent material from wrapping around and binding the shaft.

With a growing population and strict California discharge requirements, managing the 8.5 million gallons per day average flow takes a lot of resourcefulness. Luckily Santa Barbara has Ruben Mislang, the plant’s Technician Supervisor. Mislang has worked on the plant for three decades and has put in place innovative treatment equipment, including helping JWC Environmental develop its Auger Monster® wastewater screen. Two are installed in the headworks of the facility.

As Santa Barbara grew in the 1990s and the plant expanded, Mislang considered various screening technologies to maintain high operational standards and meet strict new discharge regulations. He needed to get the unwanted solids out of the wastewater entering the plant while still maintaining a clean facility and managing fluctuating flows that can go as high as 20 mgd during rain storms.

Mislang had used Channel Monster® and Muffin Monster® grinders from Southern California-based JWC for years. He turned to the company for help.

The El Estero Wastewater Treatment Plant uses two Auger Monsters, model AMD6016.

“In the early 1990s the place we were dumping the sludge had some complaints about some trash. Regulators here, like the Water Resources Board, also developed regulations to remove floatables,” said Mislang. “I suggested to JWC people like Pete (Garcia) and Rod (Graham) they had better start thinking about something to recover the solids. The upgrading of the Channel Monster into the Auger Monster was starting here.”

About a dozen prototypes later Mislang got what he wanted: a wastewater screen that reliably removed solids like rags, condoms, tampons and trash, in ground up form while also producing a clean, dry discharge that passed the paint filter test and was easy to dispose of.

Since the installation of the Auger Monsters in 1997 there have not been any pump clogging incidents at the plant, according to Mislang. In addition, a troublesome centrifugal pump in the scum line that would clog on plastic trash now runs smoothly, saving staff time, money and headaches.

The two Auger Monsters, model AMD6016, are located in the headworks building of the El Estero plant and are about 25 feet below grade level. The system consists of two parts that are lowered into the channel and bolted into place - the Channel Monster® grinder and the Auger lifting screw. The Channel Monster is a proven grinder technology that turns large solids into more manageable pieces and breaks up clumps so the washing cycle can remove more fecal material.

Two large screening drums rotate to allow tremendous flows of wastewater, up to 33 mgd for this model, while guiding all solids into the central grinding and screening zone. Solids pass through the grinder and into the screening trough where the shaftless auger captures and lifts solids out of the channel while washbars on either side of the trough flush fecal material through the screen and back into the plant flow for further processing.

As solids are lifted to deck level for discharge they are dewatered. A new compaction zone is now available from JWC that further dewaters and compresses the screenings before they are discharged. Screens are available with 3, 6 or 8 mm perforated openings.

Developing the Auger Monster was a labor of love for JWC engineers and a bit of an odyssey for Mislang. He first saw a rough mock-up of the Auger Monster in 1995 and made several suggestions on how to improve the design. This included shifting the discharge chute from the side to straight down to improve the flow of material. He also encouraged the use of a shaftless auger as the lifting screw to prevent material from wrapping around and binding the shaft, a common problem with old-time comminutors.

“I’ve spent a lot of time in Santa Barbara over the years working with Ruben on products such as the Auger Monster,” said Rod Graham, JWC’s Product Support Manager. “They have a great crew and have always been very helpful and pleasant to work with.”

In 1997, JWC received the Water Environment Federation’s Innovative Technology Award for the Auger Monster’s design and operation. Over 600 systems have been installed in wastewater, correctional and industrial applications.