Photo by George Le Masurier

Comox Valley speaks out about how to move and treat our poop

by Nov 29, 2018News, sewage0 comments

BY GEORGE LE MASURIER

Considering the potential property tax implications and long-term environmental impacts of reimagining the Comox Valley Sewer System, there was relatively small group of people at the first of two public consultation workshops.

About 30 people came out to hear Kris La Rose, senior manager of water/wastewater services at the Comox Valley Regional District, describe the process for redesigning the sewerage system to meet the needs of a growing population and a changing climate for the next 50 years.

At least a third of the audience at the Sannd Trap Bar N Grill at the Comox Golf Club were residents of Area B and Courtenay. Comox Mayor Russ Arnott and councillors Ken Grant and Maureen Swift also attended.

People can also provide input through an online version of the survey completed by workshop participants.

The Comox Valley Sewer Service (CVSS) serves the City of Courtenay, Town of Comox, K’omoks First Nation and CFB Comox. Residents of Area A, B and C rural electoral areas manage their own wastewater with about 10,000 private septic systems.

La Rose said a new Liquid Waste Management Plan is needed to decide three issues: how best to move sewage to the treatment plant on Brent Road, in Area B; What level of treatment should be applied; and, whether the plan should include resource recovery — reclaiming water for purposes such as irrigation purposes or recharging aquifers.

Separate Public Advisory and Technical committees will consider public input in their deliberations and ultimate recommendations to the Sewage Commission, which will make a decision next summer.

A new plan is necessary for several reasons. The main sewer pipe, called the forcemain, that moves wastewater from the main pump stations to the treatment plant, is 36 years old. It runs through the K’omoks Estuary, under Comox Harbour and Goose Spit, then along the beach below the Willemar Bluffs at Point Holmes before turning inland a short distance to the plant at the end of Brent Road.

Rip rap installed to halt erosion of the bluffs has changed the beach and exposed a section of the forcemain, which a study last year showed was in serviceable condition for the short-term, but still presents a long-term risk. More frequent and intense winter storms put all sections of the forcemain in the foreshore at risk.

The system’s major pump stations are also operating at capacity and need to be upgraded. Expectations have changed about how sewage should be treated and the cleanliness of the effluent discharged into the Strait of Georgia.

A previous plan to replace only the Willemar Bluffs section of the forcemain and build a new pump station in Area B that would continue to receive wastewater pumped through the estuary and harbour was abandoned last year.

The cost had been underestimated by 50 percent and would have created a single point of failure for the whole system. It also had the potential to put shallow wells in the Croteau Beach neighborhood at risk. The CVRD was able to press pause and rethink a more comprehensive plan because with the forcemain in better condition than previously thought, there was less urgency.

La Rose said the plan would also consider treatment upgrade, mostly because the current plant reaches its capacity during major winter rainfalls. Stormwater infiltrates the system and boosts volumes by nearly 4 times over summer levels.

Finally, the plan will consider ways to extract resource benefits from the treatment process. Other communities treat the wastewater to a quality enabling its use for irrigation of farms and golf courses, or to reinject water back into the ground.

Some communities clean the water to potable standards, and flow it back into their drinking water systems.

The workshop was repeated in Courtenay, and there will be further opportunities for public input in the coming months.

 

HISTORY OF SEWAGE TREATMENT IN THE COMOX VALLEY PRIOR TO 1984

 

Courtenay — Primary treatment at lagoon near airpark. Discharged into estuary, and would overflow, releasing raw sewage into the estuary.

Comox — Discharged untreated sewage into estuary via pipe that crossed Goose Spit toward Denman Island.

CFB Comox — Primary treatment at a lagoon near the YQQ airport. Discharged into the Queen’s Ditch, which ran at a shallow decline and emptied offshore at Point Holmes.

 

A GLOSSARY

Advanced Primary Treatment — The use of special additives to raw wastewater to cause flocculation or clumping to help settling
before the primary treatment such as screening.

Dewatered Sludge Cake — The sludge after dewatering that is cake like, compressed. The lower the water content the better
for wastewater treatment purposes.

Digestion — The breaking down of sludge and other waste biologically by microorganisms. Results in byproducts such as methane gas, carbon dioxide, sludge solids and water. Aerobic digestion requires oxygen, anaerobic digestion the absence of oxygen.

Effluent — The final output flow of a wastewater treatment plant.

Flocculation — The process whereby a chemical or other substance is added to wastewater to trap or attract the particulate suspended solids into clusters or clumps of floc or flocculent, wooly looking masses.

Influent Screens — Screens used to remove large inorganic solids from the waste stream.

Natural Systems — Wastewater treatment systems usually biological with a minimum of mechanical components or processes, for example, constructed wetlands.

Primary Wastewater Treatment — The first process usually associated with municipal wastewater treatment to remove the large
inorganic solids and settle out sand and grit.

Reclaimed Water — Reusable wastewater from wastewater treatment such as tertiary treatment of wastewater in biological and other systems.

Secondary Wastewater Treatment — Second biological process of digestion with bacteria

Sewerage — A system of sewers; the removal of waste materials by means of a sewer system.
 
Tertiary Treatment — The use of filtration to remove microscopic particles from wastewater that has already been
treated to a Secondary Level. Anthracite coal is the filter medium used by the MWWD.

Turbidity — A measure of how clear water is in Nephelometric Turbidity Unit (NTU), invisible to the average naked eye until readings in excess of 100 are reached, typically determined by shining light through a sample placed in a turbidimeter.

Ultraviolet Disinfection (UV) — The use of ultraviolet light to kills bacteria and other microorganisms in water and wastewater.
Typically a final treatment step.

Wastewater — Wastewater is “used” water, the water leftover after its use in numerous application such as industrial, agricultural, municipal, domestic and on.

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