The COVID pandemic brought out some vulnerabilities of relying on landfilling to dispose of sewage sludges.  Not to mention the climate impacts!  One of the major issues during COVID was the lack of bulky wastes needed to stabilize wet materials such as sludges.  Construction and demolition (C&D) debris is the majority of material used to mix with biosolids.  Generally, four parts C&D waste to one part sludge is needed to prevent slumping/instability, odors, and drainage problems.

At a webinar in April, hosted by the Environmental & Energy Technology Council of Maine (E2Tech), Rhonda Forrester, P.E. with Sevee & Maher Engineers of Cumberland, Maine, explained the concerns with receiving sludges from the landfill operator’s perspective.  In Maine, they are looking to put a lot more biosolids into landfill as a result of LD1911, which passed the Maine legislature back in April and became law in early August. Simultaneously, LD1639 eliminates waste generated out of state and will reduce bulking materials effective February 2023. Maine generates approximately 20,000 to 25,000 tons of sludge annually, and although there has already been a significant shift to landfill disposal (see https://www.biosolidsdata.org/maine), at least 10,000 tons will need to go somewhere. Ms. Forrester predicted limited sludge acceptance at landfills depending on the availability of bulking materials.

At the start of the COVID pandemic, New England got a preview of the potential impacts a reduced volume of C&D debris has on biosolids management.  According to Jennifer Lichtensteiger who runs NEIWPCC’s Residuals Workgroup, this reduction in commercial wastes caused Rhode Island’s Central Landfill and other landfills in the region to reduce the acceptance of sludge. The disruptions caused some major short-term issues but the market settled itself into a new norm. The cost of going to landfill in Rhode Island, for example, is currently $150 per wet ton for sludges and grits/rags.  

The Northeast Waste Management Officials Association (NEWMOA) took a look at the overall issue of landfill capacity for municipal solids waste (MSW) in an April 2021 report titled “Solid Waste Disposal Capacity in the Northeast”.  The report was intended to “inform conversations” about the future of landfill management in the region.  The report does not specifically look at sludges or biosolids/residuals, nor does it include materials used as daily cover.  However, there are some interesting facts in the study.

Overall for the Northeast Region, 33% of MSW goes to waste-to-energy (WTE) facilities and 67% to landfills.  Over 23% of landfills in the region are expected to reach their current capacity limits within 5 years.  That number is 29% for Maine.

Taking a deep dive into the Massachusetts data, the Commonwealth has a total of 11 solid waste landfills, 7 WTE facilities and 2 WTE ash landfills. Sixty-four percent of the MSW goes to WTE facilities in Massachusetts, 36% to landfills.  For the landfills, 9 of the 13 (or about 25% of the total MSW tonnage in Massachusetts) are at capacity with three more scheduled to reach capacity by 2030.  The one other facility has permitted capacity through 2031.

According to the NEWMOA report, Connecticut has 6 solid waste landfills, 5 WTE facilities, and 1 WTE ash landfill.  However, the Materials Innovation and Recycling Authority waste-to-energy facility in Hartford recently closed. In addition, the majority of Connecticut’s bulky waste went to one landfill that will reach its currently permitted capacity by 2025. NEBRAMail recently became aware that the landfill in Manchester, Connecticut, will be shutting its gates to grit and rags disposal leaving WRRFs scrambling for other outlets.

As far as managing biosolids for the future, Forrester offered some suggestions, including increasing the area of landfills, increasing acceptance of bulking materials, and increasing beneficial uses of waste materials (both at the landfill e.g., as cover materials and to divert wastes from the landfill).  NEWMOA plans to look specifically at capacity for biosolids landfilling and NEBRA has invited NEWMOA to do a Lunch & Learn on this topic for 2023.