Risk to asking city about my high water bill?

[cannotWAIT]

My water bill is consistently about $20 higher than my partner's ($160 vs $140, this includes sewer, trash, and lighting in addition to water but water is the only variable expense), and this has been the case for years, although I just figured it out. I have a more modern water-saving dishwasher and HE front-loading clothes washer. He has an older dishwasher, a top-loading clothes washer AND a tenant whose water usage he covers! Our bathing habits are about the same--if anything I use less water than him because I'm not supposed to get my estrogen patch in hot bath water, so I keep it shallow. Lol.

Anyway since I don't have any obvious leaks within my home, my thought is to call the city and see if they can find a reason. Then it occurred to me that they might find a problem that I would be on the hook for fixing and it might be something ruinously expensive. Is this a reasonable fear? Are there other steps I should take first? A plausible explanation for the discrepancy?

I recently read a post somewhere by a woman who had something wrong with the water line to her house out under the street that the city wanted her to pay to fix but that her insurance wouldn't cover. This is the situation I'd rather not discover. But I honestly have no idea what I'm talking about so any advice at all will be welcome.

[Omy]

A serious outside issue would likely cause a much greater difference in bills. Do you have any toilets that run or do they all shut off shortly after flushing? Any faucets that drip?  Have you analyzed the bills to make sure you are comparing apples to apples? (Different locations may have different fees and different prices per gallon.)

[CNM]

In my experience, the City won't do anything to investigate a home water leak especially one with a relatively small gallonage.  They will refer back to whatever the water meter reads. 
I would double check all faucets (indoors and out) and sinks for drips to rule out anything obvious.  If you're still concerned and aren't able to locate anything, a plumber might be able to provide more guidance.

[cannotWAIT]

He lives just down the street from me so we are billed the same. I only have one toilet and it doesn't run, and only a very slight drip on one faucet (and in the past it's been much worse with no appreciable difference to my bill). I admit that I haven't crawled under the house to investigate. It's a daunting prospect. I might rather pay $240/year in perpetuity to avoid it. Maybe I should hire a handyman to look around down there?

Re: plumbers, we have a shortage. I know a woman right now with a basement full of raw sewage who is waiting three months for the next available opening. If you can imagine.

[Sibley]

Go check the meter and write down the number. Do not turn on the water, anywhere, for several hours, then go check the meter. If it changed, you have a leak.

Leak? Fix that leaky faucet. Put food coloring in the toilet tank and see if it leaks into the bowl. Yes, look under the house. If you have lawn sprinklers, check those. When you think you fixed it all, then recheck the meter.

Also consider if you have high flow faucets, toilets, etc. Look at the bill and confirm that your meter is the only one being billed for.

If you don't have a leak, then ask. Call mid cycle, not right before the bill is due.

Youtube is helpful to figure out how to fix stuff.

[SweatingInAR]

He lives just down the street from me so we are billed the same.

Look at the two bills and compare the quantity of water you used during the billing period. This will inform you of how much excess water you are using. My bill has it listed in units of "100 gallons". We usually use 10-15 units, or 1000-1500 gallons per month.

Also... For what "lighting" do you get billed? Does your municipality bill you for street lights?

My ... bill ... includes sewer, trash, and lighting in addition to water

[MDM]

Look at the two bills and compare the quantity of water you used during the billing period.

+1

There may be a difference in a flat fee portion of the bill, based on the size of the meter, called a "readiness to serve" charge.

[cannotWAIT]

He lives just down the street from me so we are billed the same.

Also... For what "lighting" do you get billed? Does your municipality bill you for street lights?

My ... bill ... includes sewer, trash, and lighting in addition to water

Street lights, yes, and they used to be the romantic amber street lights glowing through the maples and now they're the fucking high-intensity prison yard lights. I had to install blackout curtains when they switched over. They destroyed the aesthetics of my historic neighborhood and it makes me want to cry.

Anyway, I called the city and a very nice man looked at my records and said my usage dropped drastically in 2018 (when my husband left, ha) and that it did seem high for a single person. He's coming out to look at the meter and give me some dye tablets for my toilet and whatnot.