After hearing the remarkable statistic that Arlington "loses" 27% of its water, I set out to learn more about this, what it actually means, and how and if it costs us as a Town.
Eventually I turned to Michael Rademacher, Arlington’s Director of Public Works. I was extremely grateful that he made the time to sit down with me and explain this issue, in a way that even I could understand.
Everything below is based on the results of my education. For those that come to this issue with more knowledge than my English degree provided me on it, I apologize. I’ve attempted to write all of this down in a way that someone like myself could understand, so for many this will seem a bit remedial.
What is unaccounted water? Unaccounted water is any water that we received, but cannot determine what it was used for. Most of our water is measured by water meters. There are some exceptions: in the case of fire hydrants being used or maintained, for example, Arlington has to make an estimate of how much water was used. Otherwise, we measure how much water we used by totaling up the amounts from all of the water meters in town.
But before we get too far into that, we need to understand where our water comes from. We get our water from the Massachusetts Water Resources Authority, or MWRA (on the web at http://www.mwra.com/). The MWRA provides water to 51 communities in our area, including the city of Boston. For the sake of simplicity, this is how it was explained to me:
The MWRA keeps track of all the water that enters each community. At the end of a year, they know how much water they provided overall, and to each community individually. They approach each community, including Arlington, and tell us what the percentage of water we used was, and how much we then owe.
This is an important detail in understanding the economic impact of unaccounted water. For the sake of explanation, let’s assume that MWRA provided 10,000 gallons of water to all communities, and therefore need to collect $100 to cover their costs. When they get to Arlington, we’ll say for this example that we used 10 gallons, or 1%, of the water MWRA provided. Therefore we owe MWRA $1.
Back to the topic of our unaccounted water. We know that we received 10 gallons of water from MWRA. However, after totaling up the estimated water used by fire hydrants and other such things, plus all the water we measured through our water meters, we can only account for 7.3 gallons.
We still have to pay for the full 10 gallons, and we do so by setting the amount charged consumers at a rate that covers that cost.
Remember how MWRA charged Arlington based on the proportion of water it used compared to how much water MWRA provided all its customers?
Because the average amount of unaccounted water for all the communities served by MWRA is close to 15%, the amount paid by consumers in Arlington to cover unaccounted for water is necessarily higher than what is charged in communities where the percentage of unaccounted for water is lower.
So there is a certain incentive to lower the rate of unaccounted for water in Arlington. How do we do that?
First we need to understand where we think this water is actually going. Here are the likely sources:
Leaks. The lifespan of a water pipe is not unlimited. Pipes get old, and they leak more. Both water quality (we are blessed with very high water quality) and soil conditions play a major role in how long pipes last before they begin to leak a lot. The average lifespan of a water pipe is around 50 to 60 years.
Un-Metered uses we are not aware of. When we need to let water out of a fire-hydrant, we can estimate how much water was released. The Town does not believe there are many cases where water is being used but not metered, or estimated. For example, all municipal buildings are confirmed to have operating meters. However they continue to be on the look-out for this. Some examples of places you’d watch out for include practice fields that are being irrigated using some faucet long ago forgotton, or a municipal building that at some point had plumbing put in that managed to skip the meter. We don’t have reason to believe that there are any significant cases where this is happening, but we are an old community.
Old Water Meters. When water meters get to be older than 15 years, they start to measure the water that passes through them less and less efficiently. Many things factor into just how inefficient they are, the most significant of which is water quality. The bottom line though is that over time, older meters fail to measure between 5% and 10% of the water that passes through them.
Back to the question of how to fix these problems. We have been doing tests every other year to identify leaks in our pipes. Arlington is going to do this every year now, which should help to prioritize what gets repaired, by letting us spot leaks sooner. A good thing, and the costs of doing these tests has been significantly lower than the money saved by patching found leaks so far.
But is this enough? Remember how the typical lifespan of a pipe is between 50 and 60 years? We currently provide funding to our Department of Public Works an amount that allows them to replace roughly 1 mile of pipe per year. However we have around 130 miles of water pipe in town. If we’re going to replace our pipe at a rate that will keep up with deterioration, we need to double the amount we allocate for that. Of course the extra cost of doing this will get passed along to the consumer; but based on what I have learned I believe that the consumer will in the long-term save, as our system is better maintained.
This is really the same logic as you’d use when caring for your car. You can save a little money in the short term by not getting your oil changed, but the long term costs of doing so are higher.
Higher water bills hurt, but if we don’t pay more today to keep things working, we’re going to have to pay even more tomorrow.
Replacing our older water meters is a bit tougher to work through the pros and cons of. This is water that, after all, is being used even if it isn’t being accurately measured. It could be argued that all we accomplish by updating our meters is knowing where all our water is going, rather than actually saving any water that was previously lost.
It is also a hard pill to swallow, as at the individual level if you happen to have an old, inefficient water meter working in your home, then you are going to get hit with a bit of a surprise if a more reliable meter is installed and you suddenly see your water use jump by 5% to 10%.
I’d point out though that all meters need replaced eventually, and if yours is new, you are essentially subsidizing your neighbor’s water bills, paying for every drop used while others get 5% to 10% of the water they use for "free."
"Free" is in quotation marks on purpose. Remember that in the end we pay for all the water MWRA delivers to us, whether our meters accurately capture the use, the water leaks out of old pipes, or whatever.
To the extent that all water meters are as close to equally efficient as possible, the more equitable each of our water bills are. This seems to me to be the ideal. It doesn’t matter much if all the meters in town are failing to measure 2% of the water that passes through them, or 22%. What matters is that they are, as much as possible, failing to measure the same amount.
The only way to achieve this that I know of right now is to routinely replace meters when they hit a certain age.
The DPW can, working within its current budget, phase in the replacement of all water meters over the course of 4 to 5 years. If they tried to do this any faster, it’d be necessary to outsource the labor needed, and the cost would go up considerably.
With the understanding of the problem I currently have, I think that replacing our water meters is the right thing to do. If we also double our spending on repairing and replacing old pipes, getting everything on a schedule that will replace our whole system every 50 to 60 years (which is the typical lifetime of a pipe before it is likely to fail or leak substantially), we ought to see our unaccounted for water drop to a rate that is below average for our area.
This is worth doing, as it will lower the amount of water we receive from MWRA, and that will lower all of our water bills, eventually saving us all some money.
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