During the 1800s and well into the 1900s, towns and cities along the Merrimack River, from New Hampshire through Massachusetts, thrived because of the river. Mills and factories used the river's resources to produce goods that were shipped all over the country.
But the damage to the river from these booming industries was profound. Pollution in the form of raw sewage, dyes, and other chemicals virtually killed the river. It was not an unusual sight to see the water turn colors of various shades.
Water quality studies began in 1908, with a State Board of Health investigation. The study determined that untreated wastes from a population of 270,000 was being discharged directly to the river, but that citizens were primarily concerned with the appearance of floating grease, a by-product of wool scouring operations. A follow-up report recommended that communities contributing pollution build individual treatment plants. The recommendation was not acted upon.
A 1923 Department of Health study found that about 114 million gallons of raw sewage from Lawrence, Lowell and Haverhill were being discharged into the river daily. A summary called for construction of a trunk sewer to collect these wastes and discharge them into the ocean, off Plum Island. By 1928, however, another Public Health Department investigation disclosed that industrial development had slowed and some industries were curtailing operations. The result was a decline in discharges to the river and interest in construction of wastewater collection and treatment works understandably waned.
The Merrimack Valley Sewerage District and the Merrimack River Valley Sewage Board were established in 1935, but federal funding was not forthcoming, so the long-recommended trunk sewer remained just that - recommendation.
Key, subsequent investigations included a joint study by the state Department of Public Health and the Federal Public Works Administration in 1937, a study by Thomas R. Camp in 1947 and an update of that study in 1963 by Boston environmental engineers Camp Dresser & McKee (CDM). The 1963 report recommended cleaning up the Merrimack by building individual treatment facilities in certain areas and regional facilities elsewhere. The report called for one regional facility to serve Lawrence, Methuen, Andover and North Andover, the communities would ultimately comprise the Greater Lawrence Sanitary District (GLSD).
The Greater Lawrence Sanitary District was established by Chapter 750 of the Massachusetts Acts of 1968 for the purpose of building, maintaining, and operating a system of sewage collection and disposal for the City of Lawrence, the towns of Methuen, Andover, and North Andover. The District facilities have been operational since April 1977. The Town of Salem, New Hampshire joined the Greater Lawrence Sanitary District through enabling legislation, Chapter 387 Acts of 1982 and written agreement.
A Commission consisting of seven members (three from the City of Lawrence, two from the City of Methuen, one each from the towns of Andover and North Andover), and an eighth non-voting member from Salem, New Hampshire oversee the District. The Executive Director who is appointed by the District Commission implements decisions made by the Commission. The District employs approximately 46 people, of whom approximately 34 are represented by employee unions.
The treatment facilities provide the District with the capability of processing up to 52 million gallons of wastewater per day. Major process components included in the treatment system are primary sedimentation, biological oxidation, secondary clarification and treated effluent chlorination.
- The plant's centrifuges were received from Germany.
- The plant receives approximately 900 million gallons of wastewater monthly. It would take one hundred thousand tanker trucks (at 9,000 gallon each) to deliver this amount of wastewater.
- 4,500 cubic yards of concrete were used to complete Contract 1.
- 770 tons of steel was used to complete Contract 1.
- 55 people worked on Contract 1.
- On occasion, fish do penetrate the plant from the river. Most do not survive the trip through the sewers and main pump station to the plant. All fish are stopped at the screens at the plant head-works and therefore do not ever enter any of the plant tanks.
- The plant has attracted all sorts of wildlife including hawks, bald eagles, bluebirds, ducks, rabbits and white tail deer.
- Somebody robbed a bank in Methuen in the early 1990s. A dye bomb had been placed with the money and went off. The robber threw the money that had been dyed down the sewer. The money was received at the plant and the plant notified the FBI as a result.