GLSD – The Greater Lawrence Sanitary District (GLSD) located just north of Boston treats the wastewater of Lawrence, North Andover, Andover, Methuen, Massachusetts; and Salem, New Hampshire. Two main collection lines on both sides of the Merrimack River collect the wastewater from these historic communities and convey it to the Plant for treatment.

Over the years GLSD’s antiquated screening system created high operating costs. The old catenary screens were extremely maintenance intensive and the coarse openings removed very little debris except major solids. This caused further maintenance and process issues downstream within the plant. Additionally, the old catenary screens would soon be overwhelmed with the expected increase in flow from the present 110 mgd to a future peak of 165 mgd.

With the new peak flow projections, it became clear that renovation of the headworks portion of the Plant would bring multiple benefits to the overall operations. Wright-Pierce, a consulting engineering firm with multiple offices in the New England area, was selected to design the upgrade.

In 2005, after a detailed evaluation and site visits to existing installations, GLSD chose the Headworks^® Inc. Mahr ^® Bar Screen to be installed in the sewage treatment plant. The three screens Headworks provided have an overall length of approximately 17 feet and 5 feet wide, with a screen field length of 8.25 feet. They each weigh a whopping 4,628 pounds and are installed at an angle of 75 degrees. The bar spacing is 3/8 inch, allowing for greater capture efficiencies.  The screenings are discharged into the chute of a Headworks’ Transpactor for dewatering and removal.

This robust headworks system has been running for over two years now and the GLSD is extremely pleased with its performance and minimal maintenance.

To learn more about how Headworks^® can solve your plant’s unique challenges, contact our Team.