The Ecologist

 
Orca watching in Puget Sound with Jim Maya. Photo: Robbert Michel via Flickr (CC BY-NC-ND).
Orca watching in Puget Sound with Jim Maya. Photo: Robbert Michel via Flickr (CC BY-NC-ND).
More articles about
Related Articles

Sewage treatment essential to save Puget Sound orcas

Dr. Sierra Rayne

20th December 2015

Orcas from Puget Sound and the Strait of Georgia are under threat,in large part due to toxic organic compounds in the marine food chain, writes Sierra Rayne. To give them a fighting chance, the nearby community of Victoria, British Columbia must install advanced sewage treatment - rather than just dump its wastewater largely untreated into the orcas' ocean home.

It's primarily the toxic organic compounds in the sewage that are of primary concern. Mother Nature is not very good at processing these chemical delights, and they bioconcentrate and biomagnify up the marine food chain to very high levels in the orcas.

Kathleen Haase's excellent article about the 'Fragile Waters' in which orcas of the Puget Sound and Strait of Georgia live highlights the threats these majestic animals are under, and calls further into question the ongoing delays for advanced sewage treatment in Victoria, British Columbia.

The decades-long debate over Victoria continuing to dump its relatively untreated sewage into these waters is a first-hand example of mixing bad politics with bad environmental science. The city is one of the last major cities north of the US-Mexico border to not use advanced wastewater treatment.

Those opposing sewage treatment - including some scientists - claim that "it's mostly organic matter, and Mother Nature's really good at processing that."

Yes, sewage is mostly organic matter, and while this may lead to some localized eutrophication in the surrounding marine system, that's not what we're most concerned about when it comes to the orcas.

It's primarily the toxic organic compounds in the sewage that are of primary concern. Mother Nature is not very good at processing these chemical delights, and they bioconcentrate and biomagnify up the marine food chain to very high levels in the orcas.

Victoria's sewage is laden with pharmaceuticals and personal care products, industrial chemicals (e.g., PCBs, PBDEs, PAHs, etc.) and pretty much anything else that can fit in a toilet bowl, bathtub, sink drain, and all the various domestic and commercial sources feeding into the wastewater system.

For that, say scientists, the city needs to implement a stricter 'source control' regime to educate citizens about flushing noxious substances.

Source control is not a short- to medium term solution

The source control notion has been promoted by vested interests across the political spectrum - including representatives of 'green' parties - but it will not address the problems in time. Source control proponents fail to answer some basic questions:

  • What about all the businesses that need to discharge their industrial wastes somewhere? What should these industries do, not discharge their wastes to the sewer system? And do what with them instead? Install expensive individual on-site treatment systems? That would probably be far less efficient than just building a single, central municipal system. And what would these businesses do with the byproducts of their individual on-site wastewater systems, if that's the route we took? We are left with more problems to deal with than the centralized sewage plant option.

  • Substantial quantities of pharmaceuticals (and other compounds) taken by humans pass through the body in an unaltered form and are excreted in our wastes. Alternatively, sometimes our bodies alter these precursors into equally nasty compounds that are also excreted. How do we source control this? By not going to the bathroom? By outlawing pharmaceuticals and all other nasty personal care products and commercial chemicals? How would we confirm source control measures are working? Massively expensive house-by-house monitoring programs that would cost unimaginable amounts of money (it would make the central treatment plant look dirt cheap)? Checkpoints to confirm nobody is bringing any problem compounds -- which are in everything from soaps to electronics to furniture -- in from neighboring communities? Voluntary compliance (like self-policing traffic violations, clearly an ineffective non-starter ...)?

  • A lot of the industrial chemicals contaminating the orcas' home are in the products we wash (i.e., textiles, plastics, etc.), and they come out during washing (e.g., washing machine, sink, dishwasher, car on the driveway, etc.). So what should Victoria residents do? Not wash their clothes, towels, sheets, rugs, etc.? Or maybe Victoria should require every single residence and business in the city to contain only materials that do not leach toxic chemicals into wash waters? While this is an ideal long-term objective for society to work towards, it is practically impossible in the medium-term because of all the legacy consumer and industrial products already existing in homes and businesses, and the difficulties of enforcement.

The ongoing releases of PCBs into the environment shows source control measures cannot deal with legacy stockpiles of toxins that will continue to leach out, thereby requiring collection and treatment for the foreseeable future. Sewage integrates our legacy stockpiles of toxins, and will continue to do so for decades, if not centuries.

In the interim, as we work towards a completely non-toxic society over the remainder of the 21st century via educational and regulatory frameworks, we need to treat all our wastewaters to protect the ecosystems in the here and now. It does no good to seek to protect the orcas in the long-term if we kill them off in the short-term.

Treatment opponents using 'merchants of doubt' tactics

Other anti-sewage treatment concerns such as purportedly higher rates of traffic accidents caused by wastewater treatment plants are so absurd that they don't even warrant a serious reply.

Greenhouse gas emissions from the electricity used to operate sewage treatment plants can be mitigated by using renewable energy sources (which the Victoria region has in abundance; 90% of BC Hydro's generation is already produced by hydroelectric means).

Then there are the 'merchants of doubt' type claims that advanced sewage treatment plants would not remove all the problem compounds in the wastewater stream. No, the removal rate for all toxins is not 100%, but for many toxins it is very close.

To go along with our study on toxic compounds such as PBDEs (a flame retardant present at up 30% or more by weight of a wide range of consumer materials) in the orcas from the Puget Sound and Strait of Georgia regions, we also looked at the removal rate of these compounds in an advanced wastewater treatment plant.

An overall removal efficiency of 93% was observed for PBDEs, meaning that sewage treatment removes a massive portion of these toxins and prevents them from reaching aquatic systems.

Similar removal rates are obtained for other highly hydrophobic (water-hating) toxins such as PCBs, DDT, PAHs, etc. Even for many polar emerging contaminants, removal efficiencies via sewage treatment can reach nearly 100%. Choosing not to fix a substantial part of the problem for the simple reason that the entire problem cannot be fixed at once -- as some sewage treatment opponents argue -- is philosophically incoherent.

It's not just the orcas - the whole environment is out of balance

As long as the sewage plant biosolids (residual 'sludge') that contains all these toxins is disposed of in a responsible manner (e.g., engineered landfill, incineration), a negligible quantity of the toxins will return to the environment in any meaningful time frame.

It goes without saying that using biosolids as fertilizer or other forms of soil amendments is a very dumb idea. Purposefully taking compounds out of a water stream because they are toxic, and then spreading them all over the landscape where they can re-enter the same aquatic system to cause problems again -- or enter the terrestrial food chain, is utterly irrational.

The orcas in the Strait of Georgia, Puget Sound, and the Strait of Juan de Fuca (collectively known as the Salish Sea) are a sentinel species, which means their health is a bellweather for the overall health of the ocean environment. Since the orcas are not doing well, we know entire the marine system in which they live is not healthy.

Moving Victoria into the 20th century, never mind the 21st century, with advanced sewage treatment would go a long way towards improving the health of the orcas' home.

 


 

Dr. Sierra Rayne is an independent scientist and environmentalist currently living in Saskatchewan, Canada. He completed his Ph.D. in Chemistry at the University of Victoria from 2000 to 2005 while working on the environmental fate of toxic organics such as PBDEs and dioxins in the orcas' home waters.

 

Previous Articles...

ECOLOGIST COOKIES

Using this website means you agree to us using simple cookies.

More information here...

 

FOLLOW
THE ECOLOGIST