In order to keep up with the rising population, increased demands and tougher regulatory requirements, the U.S. Army Schofield Barracks, Hawaii’s largest Army post, recently upgraded its wastewater treatment facility. The result was improved efficiency and water quality, and decreased environmental impact on the region.
The project was spearheaded by Aqua Engineers of Kauai following a contract with the Army to privatize the facility. Key to the project’s ultimate success was technology from JWC Environmental in Santa Ana, California, and GE Water and Process Technologies.
The goals for the facility upgrade were both specific and challenging. The plant needed to go from R2 quality effluent to R1 quality effluent suitable for reuse in agriculture and irrigation applications, and the crew also needed to increase plant capacity by roughly 30 percent — from 3.2 to 4.2 mgd. Another requirement was providing a surge capacity of 15 mgd to handle Oahu’s frequent rainstorms, which further increased the design challenge. On top of that, the total project was working under capital constraints that needed creative solutions to lower the overall project cost.
Solution and Results:
Aqua Engineers recommended General Electric’s ZeeWeed MBR technology to achieve the R1 quality effluent desired. This advanced wastewater treatment system uses rugged hollow-fiber, ultrafiltration membranes in order to protect the system from clogging and damage.
JWC Environmental recognized that protecting the membrane is critical in these types of MBR systems. The suggested solution was the Bandscreen Monster because of its ability to provide the level of protection required by membranes due to the entire screening operation being done on the inside of the screen. This prevents any opportunity for debris to bypass or carry over the screen and get to the membrane itself.
Originally, the project design called for building a completely new separate screening facility downstream from the existing installation to accommodate the new screens. However, in working with JWC, the need for a separate screening structure was eliminated, enabling the facility crew to replace the old 6 mm screens with the new 2 mm ones in the same channel. This creative approach resulted in a design change that saved about $1 million in infrastructure and screen costs.
The Bandscreen Monster offers high capture rates and is able to remove a wider variety of waste solids, particularly small solids, like trash and hair, better than traditional screens. The product is often specified to protect sensitive membrane bioreactors so they can run more efficiently and with less maintenance. Unwanted solids are captured on the UHMW plastic panels (with 2, 3 or 6 mm openings) and lifted to the discharge level where a spray system washes solids into a Screenings Washer Monster, used for washing, dewatering and compacting the screened debris.
Using the latest water treatment technologies available from GE and JWC Environmental, Aqua Engineers improved the local water quality and made more than 1 billion gallons of high-quality, recycled water a year available for nonpotable uses.
The Schofield Barracks wastewater treatment plant upgrade enabled the plant to provide premium-quality recycled water to irrigate lawns, golf courses, parks and other sites on base, positively affecting the nearly 28,000 military personnel, their families, and civilians who work on base and nearby.
The upgrade has turned the plant into the largest privately owned R-1 facility in Hawaii, and enables the military to conserve water, decrease pollution and contribute to the sustainability goals of the facility. After the upgrade was completed, the treatment facility was awarded a Global Ecomagination Leadership award for employing the latest technology to achieve significant environmental and operating improvements to meet community needs.