We flush and forget, but should bio-sludge go on crops? Bellingham Council considers
Bellingham officials are looking for a more ecologically sound way to get rid of the “biosolid” sludge that’s a by-product of the sewage-treatment process as they move forward with a $220 million project to replace the incinerators at the city’s Post Point Wastewater Treatment Plant.
Those 30- and 40-year-old incinerators currently burn the biosolids — a nutrient-rich goo composed of everything that’s flushed down toilets and washed into kitchen drains after the water is filtered, said Eric Johnston, director of the Public Works Department.
One method city officials are considering to dispose of those biosolids is “anaerobic digestion,” which will turn it into fertilizer.
But some residents are expressing doubts about its use on food because of possible toxins — even though the state Department of Ecology and the U.S. Environmental Protection Agency have approved its use for commercial agriculture and home gardens.
“We are at a critical junction right now for making those decisions with funding opportunities and planning,” said Kirsten McDade, pollution prevention specialist at RE Sources for Sustainable Communities in Bellingham.
McDade told The Bellingham Herald that the only state and federal regulations on biosolids from a contamination perspective are metals, not the “forever chemicals” whose dangers are not fully known.
Residents have reached out to City Council members, and also are expressing their concerns at the city’s Engage Bellingham website, where comments are posted with names removed.
“I would like to know what research has been conducted on that and what testing will be done so that we know it is safe, i.e does not include toxic metals, plastics, etc.’,” wrote one resident.
Whatcom Family Farmers doesn’t have a particular stance on the issue, spokesman Dillon Honcoop told The Herald.
But he said the group is interested in learning more about the contaminants and their possible lasting effects.
Current wastewater process
Treated wastewater is currently piped into Bellingham Bay, but the solid material that congeals in settling tanks at Post Point is burned in the incinerators.
The remaining ash is trucked to landfills, Johnston told the City Council in a presentation on Monday, April 11.
Those incinerators break down frequently, and operators have to buy spare parts on eBay or make them from scratch, Johnston told the council.
Further, the city doesn’t want to burn the sludge anymore, because it sends pollution into the air and disposing of the ash is costly and it increases truck traffic at Post Point near the Fairhaven waterfront.
Digestion process
In its 2018 Climate Action Plan, approved by the City Council, the city wants to switch from burning the biosolids to a treatment process called anaerobic digestion, using bacteria to reduce the sludge to natural gas and organic matter that can be turned into fertilizer.
A decision isn’t due until at least April 25, when another discussion is scheduled.
But the idea of spreading treated human waste on crops is getting pushback — mainly because of microplastics, heavy metals and so-called “forever chemicals” such as PFAS and PFOA compounds found in the waste stream that remain in the treated sludge.
PFAS and PFOA are acronyms for perfluoroalkyl and polyfluoroalkyl substances, omnipresent contaminants found in soil, water and air, and whose long-term effects are still being studied.
“Questions have been raised by the community regarding the safety of land application of biosolids specifically related to PFAS and PFOA compounds,” said Council President Hannah Stone at a discussion Monday, April 11, in the council’s Committee of the Whole.
“The city administration and staff have questions as well,” Stone said.
Are they safe?
Both Ecology and the EPA allow treated biosolids to be spread on crops and used in other ways.
“After almost 40 years’ experience managing them in Washington, what we’ve learned is that using biosolids according to rules and well-established guidelines is considered safe. While studies are ongoing to fill information gaps in the chemical composition of biosolids, they are a beneficial product resulting from treating domestic sewage in a wastewater treatment facility,” Ecology said on its website.
EPA also gives a qualified answer on its website.
“Composting is the biological degradation of organic materials in sewage sludge under controlled aerobic conditions. The process is used to stabilize wastewater solids to create a marketable end-product that is easy to handle, store, and use as a soil amendment. The end product is often a Class A, humus-like material without detectable levels of pathogens that can be applied as a soil conditioner and fertilizer to gardens, food and feed crops, and rangelands,” EPA said.
Mere presence of pollutants in biosolids does not mean that the biosolids pose harm to human health and the environment, the EPA said.
Decisions due
Every wastewater treatment plant and every facility that processes septic sludge in Whatcom County — including Ferndale, Blaine and Lynden — uses land application of its final product, Johnston said at the April 11 meeting.
Lynden offers it to its residents for compost, Ferndale spreads it on city-owned land, and Blaine’s biosolids are used in local farming, Johnston said.
April 25 is when the City Council was slated to decide if it will submit applications to Ecology and the EPA to build the anaerobic digesters and sell the treated biosolids.
But Johnson told The Herald that his staff will instead give the council several recommendations on a pathway forward, and encourage public input.
“We’re going to push that (deadline) a couple of weeks,” Johnston said Friday, April 15.
At $220 million, it will be the largest public project ever undertaken in Whatcom County — even more expensive than the proposed new jail, Johnston said.
Johnston said that city officials are using a “triple bottom line” analysis for the new biosolids process to ensure that the social and environmental impact of the project gets as much consideration as the cost.
“If we’re proposing to use the biosolids compost, how sensitive is it to that product not being used?” Johnston asked the council.
“Are we putting ourselves into a bind not having a place to put a product to beneficial use whether that’s a biosolid or some other product?” he said.
If not digestion, what?
In his presentation, Johnston said that other ways of handling the biosolids had been rejected, including gasification and pyrolysis, where the biosolids are baked into charcoal.
No one seems to oppose the digestion solution — the concerns focus solely on where the treated biosolids go.
Bellingham doesn’t have any control of that, Johnston told the council.
That’s one thing that troubles RE Sources.
“Once the biosolids leave the facility, it is no longer regulated. The state doesn’t track where it’s disposed of, it doesn’t monitor soil. So, we don’t really know. We are just under the assumption that it’s OK,” McDade said.
“When you go from sewage solids and break it down to biosolids, you are left with more concentrated solids and could in theory be left with more concentrated chemicals as well.”
“The regulation does not exist with biosolids. When we meet regulations, that does not mean we protect human health and the environment,” she said.
