ITHACA, NY – Last week, many Ithacans were dismayed to see the return of discolored water. For some, it had come back with a vengeance, darker and sludgier than before.
The return of the water issue was caused by a water main break near the Super 8 motel along Cecil A. Malone Drive, according to city officials.
Prior to that, the city seemed to be making progress on the discolored water issue, and complaints about the issue had dropped substantially. So what exactly happened with the water main, and how did the city handle the response?
Earlier this week, The Ithaca Voice talked to Water and Sewer department environmental engineer Scott Gibson to get some insight.
What caused the water main break?
Basically, at certain points in a water pipe that is expected to accommodate high-pressure water flows, there is supposed to be a block of concrete, called a “thrust block” surrounding the pipe to help reinforce it. Pressure changes due to demand or elevation changes can cause “water hammer” — spikes of high pressure — that can dislodge pipes if these blocks aren’t in place.
The main in that area is about 80 years old, Gibson says, and for some reason there were no thrust blocks put in place.
The Super 8 was doing a sewer main reconstruction in that area, and so part of the pipe was exposed. Normally, the pressure of the soil on top of the pipe had kept it in place, but the pipe was exposed during the reconstruction — and without a thrust block, there was nothing protecting it from the water hammer effect.
Why did this bring back the discolored water?
The main that broke was a 12-inch pipe and the break left it completely open, Gibson says. That means that due to the higher water pressures in the flats of the city, the pipe may have been spraying as much as 8,000 to 10,000 gallons per minute.
“When you see hydraulics like that, it basically scours the whole system,” Gibson says.”We were seeing rusty water complaints from Fall Creek, Spencer Road, Meadow, basically the entire gravity grid of the system in an instant.”
So to say that it brought back the colored water may not be exactly accurate, as the darker water caused by the main break was a result of scouring years worth of sediment build-up in the pipes, rather than the manganese that’s been the primary cause throughout the summer.
Were there any other impacts?
There could have been:
“If you’re pulling 10,000 gallons a minute out of a system you’re basically sucking the whole system out,” Gibson says. “Our clear wells, which are our tanks that hold the finished, treated water were getting drained very quickly. So there was that threat, if they didn’t isolate the leak — which they did, within about an hour — there was the threat of pulling all the water out of the filter plant.”
Long term outlook
What’s the latest on the overall water quality situation?
Gibson also explained more about the overall discolored water issue.
As touched on in previous coverage, a lot of it has to do with the new water treatment plant and a lot of unforeseen issues, such as the drought. The drought, for example, dried up the creek to the point that the water treatment plant was drawing on ground water, which has much higher levels of manganese — the source of the unpleasant color and odor — than surface water.
Gibson explained that the treatment plant’s specifications were based on a pilot study that did not predict manganese levels anywhere near as high as what they are, since the region hasn’t seen a drought this severe in at least 50 years.
“The latest theory is that we’ve probably had levels that maybe not have been as extreme, but levels that we’ve needed to treat out a long time, probably forever,” Gibson says. “The difference is that the old treatment process used anthracite coal, which readily absorbs heavy metals like iron and manganese.”
To avoid getting too heavy into engineering talk, suffice to say that the new system works completely differently, and the city has had to adjust on the fly. Fortunately, Gibson says that they’ve been able to get a better read on water quality trends, and should be better prepared going forward.
What about the recent rains?
While the recent rains haven’t been near enough to end the drought, its at least trending in the right direction. According to Gibson, water levels have seen less tail-off after recent storms. This is because the ground hasn’t dried out as much between storms, so more water actually makes it to the reservoir as opposed to be sucked up by a parched creek bed.
Tthe city’s response
What did the city do to respond?
The response to the discolored water from the main break and that linked to the drought conditions is basically the same: flush the hydrants.
Unfortunately, it seems that the solution itself creates a level of unpredictability. Flushing hydrants, as the Water and Sewer department has been doing throughout the summer to flush out discolored water, creates a smaller version of main break effect — scouring and stirring up sediment that has been sitting in the city’s aging pipes.
“We end kind of having to chase it around,” Gibson says. “We like to say first-come first serve, but it’s actually the worst conditions get the first flush, and try to treat it out that way.”
Putting the response in context:
The Water and Sewer department has about 40 employees, including labor crews, equipment operators, engineers and administrators, who are responsible for monitoring and working on approximately 103 miles of water infrastructure.
Gibson says that in a situation like the water main break last week, it becomes an “all hands on deck” operation, with everyone including the higher-level employees on the streets helping to flush hydrants and answering phones to the field the reports of water quality problems. During the peak of the issue, crews were working well into the evening, sometimes as late as midnight.
“For the main break we basically had crews around the clock flushing the system, you know, they’re called in on overtime — it’s just the way it is until it subsides. In this case it took about a week before it subsided,” says Gibson.
Gibson says that under normal circumstances, Water and Sewer may get a water quality complaint every two weeks or so. During the peak of the discolored water issue, they got around 500 – 600 calls in three to four weeks.
Could the city have communicated with the public better?
Gibson says that the number one complaint that the city has gotten has been about communication — people wondering why they didn’t know what was going on.
There are other options that the city is exploring, he says, but it’s unclear when they will be implemented. In particular, he said the city is looking into the use of robocalls, and also an option to send out mass-mailings. The latter option currently is tied to billing cycles, so not much use in an emergency.
Beyond that, however, Gibson says there aren’t a lot of easy ways to improve communication. Given the numbers above, it’s unlikely Water and Sewer alone could spare the staff to reach out to go door-to-door or make additional calls to individuals.
In spite of the complaints, however, it seems that most Ithacans have kept their calm.
“The public’s been very patient actually, I have to say. They’re a little more patient than I’d anticipate. I’d say the majority of people have been pleasant, they’ve been understanding,” Gibson says.