Poolesville Green column for the Monocacy Monocle
By Patrick Lee
The heat is on this summer. As I write, we’re just exiting several weeks of a brutal summer heat wave and but are still staring down drought conditions in much of our area. If you haven’t received an alert yet, the Town of Poolesville is asking residents to conserve and cut back on “non-essential” uses of water for the rest of the summer. At our house, that means taking fewer and shorter showers, re-using gray water whenever possible, and resisting the urge to water the withering lawn and the parched vegetables in the garden among other things. So, now seems like an opportune moment to consider the limits of our Town’s water supply and how that might impact our lives now and in the future.
For starters, you probably already know that Poolesville gets its supply of water by pumping it out of the ground via the wells spread out across the Town. Every flush of a toilet, every turn of a faucet, every sip from a fountain in Poolesville is made possible by the water that is pumped up from beneath the ground that we walk, run, and drive over every single day.
This process probably seems a bit “out of sight, out of mind”. After all, what difference does it make where the water comes from? Usually, I don’t give my water a second thought, as long as it’s there when I turn on the tap and it’s not the same color as mud. But one major implication of relying on groundwater is that there are restrictions on how much water we can sustainably pump out at any given time.
The aquifer that supplies Poolesville is limited in size (basically, it’s the same as the Town’s official boundaries) and it’s geologically cut off, limiting the total recharge (or refill) area. This means that the only way for our groundwater to be replenished is when rain or snow falls directly within the Town boundaries or immediately to the northwest.
Supplies tend to be highest in the spring and winter months, when there’s usually plenty of rain and snow to recharge the aquifer when compared to the amount of water we withdraw for daily use. Imagine a bank account flush with cash after payday and where the bills are easily taken care of. But in the summer, when precipitation decreases, the process reverses: more water is pumped out of the aquifer than what is replaced through recharge. Add in a drought and a heat wave, ratcheting up the demand for water. Now you can imagine our bank account is in serious danger of being overdrawn: little to no money is coming in while the bills are racking up.
This is why water conservation notices are sometimes needed and more fundamentally, why the Town is permitted by the Maryland Department of the Environment (MDE) to withdraw only up to a certain amount of water from the aquifer each day. While previous MDE studies have shown that the supply of water is more than adequate for a maximum population of 6,500 people, it’s not clear that will always be the case. As climate change proceeds apace, we could be in for more and more of these lame, snowless winters and drought-filled summers we’ve been seeing the last couple of years, which would have important implications for the amount of water available to the Town.
On the plus side, groundwater is generally a clean source of water. The layers of soil that the rain and snow first pass through act like water filters, removing many contaminants before the water reaches the confining rocks below. Because of this, many of the wells supplying the Town only need minimal treatment using chlorine.
However, this doesn’t mean that we can completely rest easy. In late 2022, we first learned that multiple wells supplying the Town have significantly elevated levels of per- and polyfluoroalkyl substances (PFAS). These are the chemicals that make your pans non-stick and allow the rain to bead-up on your waterproof jacket. They’re also impossible to break down naturally in the environment, which is why they’re also known as “forever chemicals”. The U.S. Environmental Protection Agency recently finalized new drinking water regulations that will mandate actionable levels for six types of these PFAS (out of 10,000), based on evidence of negative impacts to human health from chronic, long-term exposure. These regulations will require water utilities like our own to monitor for and remove these chemicals if detected levels exceed the regulatory thresholds.
Poolesville has been ahead of the game by working with the MDE to add new filters to the Town’s impacted wells and by continuing to test for PFAS. But putting these filters in place takes time and money. Indeed, in the midst of this current drought, our Town’s largest well is currently offline while the new PFAS filtration system is installed, placing further strain on our water supply.
On the fiscal front, our Town has also been proactive in joining a class-action lawsuit that seeks compensation from the companies responsible for creating and selling PFAS. The money, whenever it arrives, should offset some of the costs associated with the ongoing filtration and testing. But the cost of filtration will remain a significant (and potentially growing) part of the Town’s annual budgets in the future. At this time, the original source(s) of the PFAS making their way into our system have not yet been identified and addressed. So, there is the possibility that other wells will also be similarly affected.
So, as you sit back into your patio chair with an icy beverage or splash into your favorite swimming pool this summer, it’s worth taking a moment to contemplate the origin of all the water that made it possible. Water is our most precious natural resource and something that is easy to take for granted when it’s there. But with threats including climate change and contamination to contend with, it’s not a guarantee that it always will be.