Water Treatment - Some Comparisons

The Society occasionally gets questions about why we're using the water treatment system we do and why some other system might not be better or cheaper. In this post, I'm going to try and briefly outline the various options and how they compare.

It's first necessary to say that NOT treating our water is NOT an option. This would place our community under an immediate boil water order and expose residents and visitors to the risk of illness from water-borne pathogens and parasites. Kootenay Lake water might have been safe to drink untreated in the past, but it's not safe now. In fact, no surface water source can be assumed to be safe and when you're providing water to a community, you can't take the chance. Furthermore, as a water supplier, the Society is required by Provincial legislation to provide safe water. The required goal is something called the 43210 standard - more on that in another post. Treatment, in one form or another, is the only way to get those results.

There are essentially 2 treatment strategies: 1) centralized treatment, and 2) POE/POU treatment.

Centralized treatment is what our system uses now. All water pumped from the lake passes through this system and is stored in a reservoir for distribution. The big disadvantage to centralized treatment is that ALL water goes through this system, including water that is only being used to water the garden, wash the car and such. There is no easy or cheap solution to that problem. Our system uses filtration to 1 micron and chlorination. This is a process which has been proven safe, effective and cheap. There are other possible treatment processes, including UV, sand filters, charcoal beds and so on, but some of these are more suitable to larger municipal systems which are using large volumes of water. One concern with chlorination is the chlorine and chlorine byproducts remaining in the water we drink. Given the number of people world wide that also have chlorine in their water, this wouldn't seem to be an unknown problem, but if people have concerns, it can be dealt with at the tap with simple and cheap filters.

One additional advantage to using chlorine is that it protects against bacterial and fungal growth while the water is stored, for example, while it is sitting in a reservoir. This is a benefit that water treated with UV does not have.

From our standpoint, our centralized treatment system meets provincial quality standards, it's effective (we don't get bacteria in our water), it's cheap to operate (only a couple of hundred $$ each year), and that to fix or change anything we only have to go to ONE location, not each house on the system.

POE/POU stands for Point of Entry (where all water is treated as it enters each house) and Point of Use (where a filter might be attached to the cold water tap in the kitchen, for example). POE systems might include filtration (provincial regulations require filtration to 1 micron), UV, or some other process. POU systems generally would use some kind of filter at a specific tap but could also use reverse osmosis or distillation.

A community planning to use a POE system would need to have 100% of the residents approving and agreeing to use this system. There would need to be equipment installed at each house, the Water Society would need regular access to that equipment to service it and the equipment would be owned by the Society. The cost would depend on what process was used, but could be anywhere from $500 to several thousand $$ per house. Instead of having one service location, there would be 26 (with our community's size) and even if each system cost only $500, we'd be looking at $13,000 to install a system like this.

POU systems can be installed by anyone on any tap they want. Consumers could also have their own distillation or reverse osmosis system. Such systems alone would not be approved by Interior Health for a community water supply.

The bottom line for us is that we have a system that is working now, requires little maintenance to operate and is cheap and effective.

Water Society AGM

The Society's AGM for the Fiscal Year 2009 was held on Sunday afternoon. About 18 members attended. A few basic highlights:

Maintenance (a favourite topic on this blog) has been in high gear since last spring and many essential projects have been completed with others identified for future attention. A few items remain on the agenda to complete before winter.

So far in 2010, about 175 volunteer hours of work have been contributed to the maintenance of the system. This doesn't include the time spent by people on water teams, the Board, taking water samples, testing for chlorine, doing the financial records and so on.

Financially, the Society is in good shape. It is unlikely that we will have a profit this year given our maintenance spending, but we should be close to a break-even situation by year-end.

The new metered water rates seem to be working well and should provide the Society with about as much revenue as did the old flat-rate system.

Several other items of a routine nature were discussed at the meeting, some of which will be addressed in future posts to this space.

The meeting was followed by a potluck supper.

The Treatment Building gets the Treatment

Any of you who have shared "water duty" in the past year or two will be aware of the slowly deteriorating condition of the walls in the Treatment Building. Finally, with summer rapidly disappearing, some time on the maintenance schedule was set aside for some work on this part of the system.

There are (at least) 2 problems with the building as it was constructed: wood frame walls sitting on a concrete slab and wall finishing of drywall sheets, neither suitable for a building where
there is so much water on the floor and chlorine fumes in the air. These conditions have joined forces to start rot on one bottom wall plate and most of the drywall is crumbling from the high humidity. Recently, two volunteers removed several sections of crumbling drywall, installed plywood in its place, did some painting and caulked along the wall/floor seam to prevent water getting into the wall again.

Over the past week or so, the inside of the building has taken on a new, fresh look (at least some of the walls have, so far). New shelving is being installed, old shelving is in the process of getting some paint, pump switches have been moved to a more convenient location, and wiring has been located to facilitate enhanced pump timers and/or automatic shutoff systems. Some storage is now available for a few small replacement parts that are needed occasionally in that location: canister "O" rings, injector line foot valves, canister drain valves, etc.

As well, the floor has received a coat of new paint, corrosion on some pipes and connections has been covered over with paint, the door has been stained and trimmed to reduce sticking and new filter canister drain buckets have been obtained. All that remains, for this summer, is to stain the outside of the building. Next summer, the plan is to put on a new metal roof and complete the drywall replacement.

A similar treatment is being planned for the pressure building by the reservoir. The next time you're in the building, take note of the changes, just a few of the things needed to maintain a 30-year-old system.

Tricky Leaks

For some time, there's been a suspicion that the valve on the water standpipe below the Treatment Building has been leaking. Finally, it was obvious that something was wrong so we had the valve and the line excavated yesterday. Unfortunately, the system's plans don't really show where the line is so the digging had to be careful. Finally, however, the valve and the nearby pipe was exposed. Sure enough, there was a significant leak from the valve.

A quick cut removed the pipe and a bit of pressure from 2 pipe wrenches freed the valve which was later found to be completely worn out. Once a new valve is received everything will be put back together again.