Using Well Water to water lawn. Economic/Environmental Q

Having recently relocated to a new area, I have come across something I am not familiar with. Single family residences in an urban area with a water well specifically for watering the lawn.

Does it save water? Since it is not using city water?
Does the city water come from the same aquifer?
Does an individual electric well pump use more electricity than a city wide water system?

It certainly saves treated water, so that’s an environmental plus.
Without knowing the city, it’s impossible to know if city water comes from the same source.
The power to pump the water is probably a wash, but… you are paying for the electricity directly.

In a lot of cases, the city can take advantage of varying landscapes and equally varying aquifer depths. The city locates their water pumps in areas where the elevation (or at least the depth of the aquifer) is higher. The city then pumps their water into large tanks, and lets gravity actually feed the water to where it needs to go.

An urban resident can’t take advantage of a higher aquifer a few miles away to let gravity do the bulk of the work.

A really good example of letting gravity do the work is the city of Baltimore. Its water sources are mostly located at a higher elevation than the city itself, which isn’t difficult - since the city is basically directly on the Chesapeake Bay, its highest elevation is something like 500 feet above sea level, and its lowest elevation is basically sea level.

Baltimore’s water is pretty much all rain water and snow melt. This naturally gathers into the city’s various water reservoirs (Loch Raven, Liberty, Pretty Boy, and… am I forgetting one? This is off the top of my head). Baltimore can also pump water in from the Susquehanna River but IIRC they only do this when there is a drought and the other reservoirs are getting low. I am not aware of any water being pumped from local aquifers into the Baltimore City system, but then I am not an expert on their system and I could be wrong.

So an urban resident in Baltimore would not be drawing water from the same aquifer as the city.

On a per gallon basis, the individual well pump would use significantly more electricity than the city-wide system since most of Baltimore’s water is gravity fed and not pumped. But then the city water has to go through treatment plants, where the residential water would just get pumped up and sprayed out onto the lawn. I don’t know enough about how much energy the treatment plants use to say if that offsets the lack of pumping or not.

I suspect that the city’s water needs exceed anything they could get by pumping from aquifers; most cities have some kind of reservoir, or draw from a river.

Doing a little googling, this article suggests that at least SOME municipalities may draw from underground water supplies. "Large cities and towns usually get their water from surface water supplies or a mix of surface and ground water supplies. "

Having a well would certainly preserve the city’s water supply (assuming it’s not drawing from the same aquifer). The electricity cost would likely be higher, since hundreds of individual pumps would probably be less efficient than any kind of large-scale pump the utility uses.

As far as gravity: do municipalities typically treat inbound water (from reservoirs etc.) in any way? If so, then the water still has to be pumped up into whatever water storage / water tower does the direct feed to the consumers. We lost our water supply once, after Hurricane Irene (I think): the municipal pumping system lost power to at least one of its main pumps, so part of the water storage system ran dry. During other power outages, we never had a problem.

I would imagine it depends on the aquifer. I’m guessing in the east and eastern-central USA, the aquifers are filled as fast as they are extracted due to decent rain and snow. However, there are areas of the midwest, especially the high plains, and obviously the western deserts, where aggressive use of ground water has dropped the level of aquifers several hundred feet. Typically, this would include town supplies because there is not other major source (unless you count sucking the Colorado river dry). This is in areas where it is estimated that even if the towns and farmers stopped using water altogether, it would be a century or several before the aquifers recharged. Some locales are about to hit the wall on water supply.

OTOH, my municipality has a water charge and a sewer charge. It’s based on the water meter, so even if I water the lawn (heavily, in summer) I still pay as if it went down the sewer. There’s an storm sewer overflow retention pond nearby and I’ve wondered about pumping that to water the lawn.

I live in Ohio. We have so much ground water that a city near me dumps 350,000 gallons of well water into a river each day, for art & entertainment purposes.

Some areas don’t have the capacity to water lawns either all the time or during droughts, but private wells can be used as desired. Others towns charge a lot, so private wells bypass that, but the well water may be undesirable for home use but fine for gardens. IIRC even NYC has some private wells which exempt them from water restrictions.

My father-in-law drilled a well to water his lawn because he felt he was paying too much for city water. The reason was that his city had to expand it’s sewage treatment facility, and the way they taxed for it was to add a surcharge onto each user’s water bill. Here in SW Ohio the same thing applies. Some suburban folks will buy a tanker-truck load of water to fill their swimming pools in the spring because it is cheaper than buying “city water” in a big volume.

In my municipal water system if you don’t have a separate water meter for irrigation water you’ll end up paying for the water twice, because the sewer bill is based on the water bill even though the irrigation water doesn’t end up in the sewer.

Of course, having a separate meter for irrigation carries a minimum monthly charge even if you don’t use irrigation water, like in a rainy season or during the winter, so there’s a cost for that offsetting the savings on the sewer bill. I get around that by not irrigating and fuck my lawn, let it worry about itself.

In my city, I’ve been in both situations. In my previous house, I was on city water for the house, but I had a well for the lawn and garden. In my current house, I have 2 meters, one for the house and one for the sprinklers. Because there’s a monthly fee for the irrigation, I have the city shut the irrigation meter off for the winter.

The sewer bill is based only on the house water, with the city’s assumption that irrigation water doesn’t go to the sewer.

Yes, those reservoirs are just as untreated as any natural river or lake. They get all the treatment.

How else does he think they should fund the sewage treatment plant? Greater Cincinnati Water Works uses your winter quarter (December-March) water usage to determine the Metropolitan Sewer District bill. That puts a ceiling on the sewer bill for the rest of the year. If you use less water in the summer than the winter, your sewer bill will be reduced accordingly as well. That seems like a pretty fair system.

Milford, a suburb of Cincinnati, gets its municipal water from an aquifer next to the Little Miami River, supplying roughly 6,400 customers. I suppose they’re using the aquifer more as a pre-treatment filter since it’s ultimately river water anyway and they have a full, if small, treatment plant. The aquifer is contaminated with VOCs too, so they had to install an air stripper tower in which water is pumped to the top and as it falls down through a series of baffles or balls air is blown in from the bottom to the top taking the VOCs out with it.

The Indian Hill Water Works is barely a half mile upstream and also pumps from the aquifer, though it doesn’t look like they have any VOC contamination. They serve some 15,000 customers and also have a full treatment plant.

Cincinnati itself has a world-renowned treatment facility, but it’s certainly not one of the most efficient since we don’t have any natural reservoirs to feed into the treatment plant. Instead, water is drawn in from the Ohio River and pumped up to open reservoirs for temporary storage. This used to be done with four huge triple expansion steam engines, long since retired but still in place to keep the building from floating out of the ground due to hydrostatic pressure. New electric pumps in that building and a newer one have taken on that task. The water from the reservoirs then flows by gravity into the treatment plant below. At one point they installed an electrical generator between the reservoirs and the treatment plant to capture some of that energy, providing about 100KW, but it was abandoned for being unreliable and only a fraction of the electricity needed for the plant as it gradually evolved from coal-fired steam engines to grid power. Anyhow, after treatment, the water then flows by gravity through a four mile long underground tunnel to the main pumping station closer to the center of the city. That also had several massive steam engines, now replaced with electric pumps, to get the water to storage tanks and other booster pump stations around the region. So in this case the water has to be pumped at least twice.

Same thing here. My city water bill is separate from the sewer bill, but when water consumption goes up, so does the sewer bill, the presumption being if you’re drawing water, the vast majority of it winds up in the sewer. When I had an undetected break in the water line, the water bill went from about $80 to nearly $400 for the month and the sewer to over $300.

I don’t have a swimming pool but I think you can get a break when you fill it.

Where i live, i pay more for sewer than water. I can get a separate meter for irrigation, and only pay for water on that meter, but with a single meter, i pay for sewer on all my water.

I assume with a well, you pay neither sewer nor water, just electricity.

It may be cheaper to pump your own water for irrigation, but illegal to dump it into the municipal sewer system, so you couldn’t use it in the home. Or the week water might not be safe to drink. I can think of a lot of reasons you might use a well for your lawn but not for your kitchen.

My neighbour had one of those above-ground pools - about 4 feet deep and 15 feet diameter. I calculated that it would cost probably $130 to fill it up. So you don’t want to do that too often for a rinky-dink pool.

Another possibility with an older home was that it was on well water before the town expanded to that point and provided services. Whey I was young, we moved to a house for a few years that had a septic tank even though it was technically well within city limits and had city water. Years later the owner at the time mentioned to me they’d gotten city service.

Of course, i don’t think I’ve seen or heard of a house that was properly piped for grey water - i.e for flushing toilets, etc. (Maybe washing machine, utility sink in the basement?) I would think the more logical plumbing would be for capturing grey water ( run-off from sinks, bathtubs, laundry) to use for flushing toilets or watering lawns. But obviously, towns that forbid watering lawns during droughts aren’t going to make an exception because the water filled up a bathtub first - that leads to cheating. Otherwise, more efficient total use of water would be a good thing.

What I meant was, is the inbound water supply (that is sent to customers for drinking, bathing etc.) filtered, or treated in any way to kill pathogens - but I actually knew better than to ask: municipal supplies sometimes use chlorine or something, and a quick Google turns up this article as the first hit.

I wish I’d known about this option! Our irrigation system had a leak - and we did not know how to turn it off at the source (turns out it was an easy 30 second fix). For 36 hours, it was running constantly. Our water bill this month was really, really bad.