By Sebastian Kanally, Times Chronicle

Good news came flowing out of results assessing Oliver’s groundwater risk for pathogens, although it did not look at chemical risks in the water. 

Oliver hired Associated Engineering to conduct the Groundwater at Risk of Containing Pathogens (GARP) Assessment, which is now mandated by the Interior Health Authority. 

Marta Green, senior hydrogeologist with Associated Engineering presented their initial assessment findings to council on July 15. 

GARP determines treatment objectives for microbiology in the eight domestic wells when it comes to pathogens, viruses, and harmful bacteria and protozoa. GARP does not deal with chemical risks such as arsenic in the water. 

This means that “GARP is an umbrella term for all the ways a particular ground water source could be at risk from pathogens”. 

Groundwater can be at risk from various sources such as sewage discharge to land septic fields, leaking municipal sewage pipes, agricultural waste stockpiles, runoff into poorly constructed wells, and surface water. 

The program for identifying these potential hazards consists of four stages: Hazard screening and assessment, GARP determination, risk mitigation, and long-term monitoring. 

The report notes that they are only halfway through the assessment stage at this point, but results are looking positive. 

Despite the assessment not being completed, Green noted that “everything is looking really good so far, I am actually a little bit surprised at how amazing your filtration is.”

After saying this, Green explained that there will be some recommendations made to council at the end of the process. 

A few of these recommendations are:  

  • Completing a well protection plan.
  • Adding the well capture zones to Geographic Information Systems (GIS). 
  • Explore development permit area bylaws for the capture zones. 
  • Increase public awareness.
  • Work with farmers on education for the capture zones.
  • Conduct well head improvements.
  • Purchase equipment for each well to have real time (15 minutes) turbidity with triggers and alarms. 

These recommendations are based on certain hazard categories that are assessed, such as the water quality results, well location, well construction and aquifer type and setting. 

For example, in the well location category, if a well is within a certain distance to residential homes, the potential for water being contaminated by factors such as rooftop drains goes up. 

Kelly Mercer, director of operations explained in the meeting that they are “doing about 10 times the amount of sampling that we normally do right now.”

Mercer further explained that getting the turbidity automated, which was one of Green’s recommendations, will provide a large benefit to the town, as they are doing the tests all by hand now and lack any significant background data. 

In determining the groundwater risk, Green explained that for each water source if it is at risk it is determined to be either at risk of containing pathogens (GARP), or GARP – viruses only. 

If the water source is determined to be GARP viruses only, “you only need one form of treatment, like chlorine” Green explained. 

If the water source is considered full GARP, then you need two forms of treatment such as chlorine and Ultraviolent (UV) light.” In addition to this, a further filtration exemption might or might not apply. This means that further treatments through filtration systems might need to be looked at for the wells. 

These two different classifications of being at risk are due to the fact that there are three different types of waterborne pathogens that travel in ground water: Viruses, bacteria and protozoa. 

Viruses can be easily dealt with by using chlorine, but the bacteria and protozoa need further UV treatment or filtration. Bacteria that can be present are things such as E.Coli and Salmonella. Protozoa that can be present lead to illnesses such as Giardia and Cryptosporidium.