Tuesday, August 4, 2015

Water Water Everywhere

Pelham Reservoir owned by Town of Amherst (so don't mess with it)

The reawakening of Baby Carriage water treatment plant combined with the firing up of Well #4 is one sure sign the summer has turned a corner and we are now streaking towards the students return to reawaken our sleepy little college town.

Scenic  Baby Carriage Treatment Plant, South East Street

I'll let DPW Chief Guilford Mooring do the explaining:

The issue is not that the reservoir is low but that in the late summer demand goes up (Students come back) and the weather becomes more violent. Because the Pelham reservoirs are so small (sometimes because they are lower) the late afternoon summer storms stir up the water quite a bit. The warmer and “flasher” the water the harder it is to treat. So to avoid this issue we switch to well 4. Well 4 has a high output but is high in iron and manganese, so it must be treated, thus the Baby Carriage treatment plant must be operating. It is harder to start a treatment plant than one of the other wells so by starting Baby Carriage now and keeping Atkins online we then can adjust the flow of the other wells to meet the increase in demand as the population increases. Well 4 and baby carriage will stay on into the fall when weather patterns change and the cool temps make the Pelham Reservoirs easier to treat. So long story short, this is just our normal routine that allows us to ensure we have enough water for the population.
Of course all of us townies remember the year 1980 when the water ran dry only days after UMass opened and all the students had to be sent home. Yikes!


Anonymous said...

What does "flasher" mean in terms of water? As in "The warmer and 'flasher' the water..."

Larry Kelley said...

Guilford said he left the i out and meant to say "flashier," which he describes as "the rapid change in raw water quality."

Dr. Ed said...

Which is a fancy way of saying that water running across the forest floor, through the leaves and such, can pick up fecal bacteria from animal droppings and such.

One or two good thunderstorms and watch for folk to start worrying about E Coli counts...

Anonymous said...

It is not the E Coli that is the biggest issue as much as the organic matter itself. The organic matter can cause taste and odor issues with the finished water. It can also interact with the chlorine (that kills the e coli) and causes DBPs or disinfection by products. This is the bigger issue.


Dr. Ed said...

Larry, the untold story of the 1980 Water Crisis was that it was caused by the State Plumbing Code and the asinine belief that Amherst was Boston. And it wasn't the drought that caused it as much as the lower water levels in the towers and the inability to replenish it quickly enough.

The plumbing code did not anticipate the possibility of an entire water system loosing pressure -- the only thought is to the size of the pipe coming into a large building, not the ability of the utility to maintain pressure in it.

Lack of water was not the direct cause of this! while that was the indirect cause of why the level in the towers was too low, while the levels were too low because more water had been consumed that summer than the DPW could replenish (I presume), this was caused by not having enough water elevated high enough to maintain pressure -- too few standpipes to maintain potential maximum demand and not a high enough level in the ones that existed -- and it could happen AGAIN!

The toilet in your house has a tank -- (that's why Europeans call it a "Water Closet" or "WC") -- water stored in the tank is used to flush the toilet with the tank then slowly refilling -- slowly not only because you want water available for other uses while it refills but because to avoid "pipe hammering" when it shuts off. (If water flowing through a pipe is suddenly stopped, it's like a car hitting a tree -- done hard enough or enough times, it can split the pipe open.

If your water pressure drops, your toilet refills more slowly -- or not at all -- but it's not going to make the situation worse. The toilets UMass had did because they were the "vacuum breaker" style which rely on water pressure to shut them off after flushing. When the water pressure dropped, the toilets on the upper floors in Orchard Hill & Sylvan started to flush continuously (the Southwest towers have "jockey pumps") and thus created a greater demand from an already insufficient supply and the pressure began to drop further.

This wasn't an emergency -- yet -- but as the pressure dropped, more and more toilets started to flush continuously, consuming exponentially more water and dropping the pressure even further, causing yet more toilets to start to continuously... It mushroomed just like the "Blackout of 1966" where what would have been a local blackout in Upstate New York (caused by lightning strike on a power plant) wound up plunging most of the East Coast into darkness.

With all the toilets on campus (that still had water) continuously flushing, the entire Amherst water system was unsustainable -- this is where the record water consumption came from and at this point there was no way that enough water could be put back into the system to bring the pressure back up to the point where the toilets would shut off, and there wasn't time enough to shut them off manually.

The same thing would have happened in Boston except that in Boston the entire system is so much larger that a half dozen large buildings (or a broken water main) can't drop the pressure system-wide the way that happened in Amherst. Something similar back in the 1970's caused a "single alarm" fire to expand into a inferno that consumed a good chunk of Chelsea (MA) notwithstanding the valiant efforts of firefighters from as far away as New Hampshire. The antiquated and dilapidated water mains were unable to supply the fire trucks and they had to run pumper-to-pumper, with each truck pumping into the next so as to bring water in from where the hydrants were able to feed a fire truck.

And Larry, what happened in 1980 could happen again. I remember one afternoon in the 1990's when people were very worried about a broken water main as they watched the tower levels drop, people who knew more about this sort of thing than I do were worried....

The infrastructure behind the hydrants was unable to maintain pressure and

Anonymous said...

Was there a problem in the late 80's as well? (That's when we moved here - I can remember hearing about water tower issues)

Larry Kelley said...

I don't think so. That could be just the usual complaint about how expensive water towers are to repaint (many hundreds of thousands). Umass has been trying to give us the one on the top of the hill on East Pleasant Street for a while now.

We did almost have a problem with the water supply because of the 2011 Halloween snowstorm, but fortunately MEMA shipped us a few generators pronto.

Anonymous said...

Larry (and also Guilford and Ed),

This has been one of your more interesting and informative blog posts - thank you!

Guilford uses the acronym DPB when referring to the result of chlorinating raw water from shallow surface sources. This raw water typically contain more organic compounds than water from wells, rivers or deeper reservoirs, so treating with chlorine can result in small amounts of chlorinated organic compounds, which while not acutely toxic, may pose serious long-term health risks. (Ironically, that's only one letter away from the acronym PCB for polychlorinated bi-phenols, a related class of chlorinated organic compounds, used for things like electrical transformers, and which have proven to be extremely toxic.)

With this in mind, why isn't Amherst using other non-chlorine-based disinfection methods, such as ozone-treatment or UV exposure, to disinfect its drinking water supply?

- A Water Drinker

Larry Kelley said...

Guilford, who is very busy at the moment, said:

"The problem is that you need a system that provides a disinfection residual throughout the water distribution system. Ozone and UV work well but you often need to have additional systems or treatments to maintain the disinfection residual."