We often say, “History is all around us,” but sometimes history is underneath us.
Last week, we talked about the history of the vast sewer system that lies beneath South Portland. We continue this week with a look at how sewage was treated by our community in the past, and the changes that came about with the construction and opening of our sewage treatment plant in 1978.
Wastewater is treated in these bubbling aeration tanks before heading through clarifier tanks. Courtesy photo
Many people may not realize that before we had a sewage treatment plant, all of South Portland’s raw sewage was dumped into the Fore River and Portland Harbor. In the 1970s, I can remember being told not to play in the water coming out of the pipe on Willard Beach. I must admit, though, that I hadn’t realized precisely what that meant.
I gave my friend Mark Lorello a call to discuss the early system. Mark started working as a lab tech at the sewage treatment plant in 1979 and retired from the city in January, 2017. I asked Mark about the early sewage system and was surprised to learn that there really wasn’t any screening at all.
Prior to the treatment plant, if you flushed a toilet, the contents would literally flow down the pipe via gravity to whichever outlet was closest to your home. These outlets were spread across our coastline.
When I delicately asked him about potential floating matter entering the harbor, he told me that they had a term back then for what I was wondering about: “R.O.s” (recognizable objects). According to Mark, the contents coming out of the pipe into the ocean very seldom had any R.O.s, something that I realized when I visited the sewage treatment plant recently and saw the inflow coming into the plant. Surprisingly, after a toilet is flushed, by the time the contents reach the plant, it all pretty much looks like what you’d think storm water would look like.
Our modern treatment plant has computerized systems that allow staff to monitor the flow going through the treatment plant. Courtesy image
Planning for the sewage treatment plant started long before its construction.
In May, 1965, the city of South Portland hired an engineering firm, Fay, Spofford & Thorndike, Boston, to conduct a study of our sewer system and to make recommendations. In 1966, the city council approved moving forward with the plans for improvements to the sewer system, including the future construction of a sewage treatment plant. City manager Bernal Allen recommended issuing municipal bonds to help pay for it. In 1968, the city purchased the seven-acre site on Waterman Drive for $18,750. In 1970, the city council approved a $281,500 expense related to planning needs to build a sewage treatment plant.
The wheels sometimes turn slowly on large projects, however. The actual groundbreaking for the plant on Waterman Drive didn’t happen until November, 1975.
The designs for the treatment plant were drawn by Fay, Spofford & Thorndike. The city hired Harvey Construction Company, Manchester, New Hampshire, to construct the plant on the mud flats just west of the new Waterman Drive. It took almost three years to construct the plant – bringing in fill to create the base of the site, driving piles to support some of the new buildings, constructing the buildings themselves, and then installing all of the equipment inside. The treatment plant also needed to be connected to our network of sewers, which had previously all been flowing out into the Fore River and Portland Harbor.
Sewage flows with gravity, so wherever the low places of the system were, pump stations were installed to pump the sewer flow to a higher elevation where it can flow again via gravity toward the next pump station. There are currently 28 pump stations across the city that help maintain the continuous flow through the system, from all points to the treatment plant. The sewage treatment plant first began operation in August, 1978.
Sodium hypochlorite is used as a disinfectant at the treatment plant; excess is removed before the water is discharged into the harbor. Courtesy photo
After an upgrade of the plant in 1995, they can now handle up to 23 million gallons of wastewater per day. Before the water gets to the plant, it will go through screens in the sewers which collect about four tons of material per month. There are another roughly four tons per month of “grit” (solids like sand and other particles that settle out of the wastewater). The grit and screenings are collected in dumpsters and are shipped out to the ecomaine landfill in Westbrook.
When the water flows into the plant, it passes through many different holding tanks, providing both a physical and biological treatment. Through aeration/bubbling and beneficial microorganisms that eat and multiply, the treatment results in about 95 percent of the suspended waste materials settling out (forming sludge, 90 tons of which is sent to the landfill each week). The remaining water goes through a secondary treatment from May to October; sodium hypochlorite (the same active component in household bleach) is added as a disinfectant, and any excess is removed before discharge.
When the water is finally discharged into the Fore River, it is considered clean (not clean enough to drink, but safe for discharge into the harbor).
In more recent years, the city has been focusing on sewer separation projects – separating the storm water and sewage into their own systems. There used to be 33 combined sewer overflows (“CSOs”) which would deliver both sewage and storm water to the treatment plant. Storm water, which enters the system through storm drains and catch basins, would sometimes result in an overflow of the system during heavy rains; that occasional overflow would have to be discharged, untreated, into the harbor. Since the sewer separation projects have made a lot of headway, only four CSOs are left today. With the systems separated, the city is better able to ensure that all sewage will be treated, even on rainy days.
The engineering department at Water Resource Protection is an important element of having a functioning, reliable wastewater treatment program. The department supervises the entire sewer system, conducting an asset management program. The program oversees every aspect of the system, from the sewers themselves, to the pump stations and the equipment and facilities at the treatment plant. The city hasn’t always had an engineering department.
Before Brad Weeks was hired in January of 2008, the city had eliminated the prior standalone engineering department and was instead hiring out engineering services when they needed it. This represents the difference between operating in crisis mode (when you hire engineers to fix a problem that has occurred) vs. being proactive and trying to prevent problems from happening.
Our engineering department in South Portland takes pride in going even further – doing predictive diagnostic maintenance – where they are regularly monitoring all of the equipment throughout the system. They take baseline readings of equipment performance and, as future inspections are made and readings taken, they compare the measurements against manufacturers’ recommendations to try to predict when future problems may occur. Depending on the likelihood and consequences of failure, they may put in a request for funding to replace a part of the system to prevent a serious malfunction.
We’ve come a long way since discharging our sewers directly into Portland Harbor. Altogether, the sewers, catch basins, pump stations, and treatment plant form an entire system to safely collect and dispose of what starts as hazardous materials and ends up as clean water discharged into the harbor.
Upcoming South Portland Historical Society programs
On Thursday, Feb. 16, at 6:30 p.m., South Portland Historical Society’s own Seth Goldstein will give a lecture on “The Lobster and Aquaculture Industries of Maine: Past and Present.” The program will be held at SoPo Seafood, 171 Ocean St. Admission is free for current members of the South Portland Historical Society; $10 for non-members.
On Saturday, Feb. 18, at 6:30 p.m., Seth Goldstein will lecture on “African Enslavement, the Underground Railroad and Abolition in Greater Portland.” The presentation is at Lincoln & Main Electric Bike Café & Winery, located at 93 Main St. Admission is free for current members of the South Portland Historical Society and $10 for non-members. Food and beverages will be available for purchase.
For more information, visit the historical society’s Facebook page, email sphistory04106@gmail.com, or call the society at 207-767-7299.
Kathryn Onos DiPhilippo is executive director of the South Portland Historical Society. She can be reached at sphistory04106@gmail.com.
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