Well, I live with a couple of roommates, and we all get along fine. The lease is in my name, and it was originally my place, and they moved in, and I'm not charging anyone utilities. Just to set that straight. Now, The girl roommate is very nice and everything, but I notice she is always washing things in the washer, just about 6-7 days a week. The first couple of weeks I really wasn't concerned because I thought, maybe she didn't wash anything, and now she's sort of catching up. Then she got a girlfriend (yes she's gay, but I don't mind, it's really whatever.. ) so I thought, maybe she's washing her girlfriends clothes or something and she's playing catch up for her.. I know she shouldn't do it, but, whatever, it's not a big deal.. But she's been here a couple of months now, and she's still washes things like everyday. So far, she's ruined the shower curtain, she washes things like mats, shoes, a futon cover, and even a big backpack, that made the washer shake and make loud concerning noises. I've never seen anything like it before.. It's like she's trying to wash anything that you can possibly think of.
This concerns me because 1, she's monopolizing it all the time. 2, I'm worried our water bill a little. 3, will all these foreign objects break it? 4, it's right next to our bedroom, making it pretty hot all the time and it can get really loud.
I just want to know exactly what I should say. I KNOW I have to and WILL talk to her, but I'm just not sure how I should go about it. When I asked her why she was even trying to wash the shower curtain, she said shower curtains get dirty with soap scum, did you expect me to leave it dirty where I have to shower?
I don't want controversy, and I want it to stop. Suggestions?

It sounds like she may have OCD. Has she ever been treated for this washing problem, do you know? It sounds like washing things takes up an awful lot of her life.

Yes, she could destroy the washer by washing large, heavy objects (especially if they shouldn't be washed in a washing machine), plus run up the water bill. Do she take a lot of showers or baths, and use a lot of towels? Does she wash the dirty dishes more than once?

Since you are paying the utilities, how about showing her an older water bill and a newer one, and mention the increase. I have no magic words for you to say. If this is truly OCD, it will take more than your words to change her behavior.

Tell her that from August on, you will be splitting utilities 3 ways with slightly lower rent. The washer uses hot water too, probably, so that's another bill. And since your name is on the lease, you get to say what goes in the washer or not. I would limit anyone's laundries to to a week and she can go to a laundromat for the unusual items. Put it in writing.

I'm not sure if she's been treated for OCD, but she works at a clinic.. Just sort of ironic is all. She does seem to shower 1-2 times a day, but I don't feel it's an unusual amount or time she's in there. She sometimes goes without doing a couple dishes for a day or so, which is totally fine with me, so there's no obsessive cleaning there. And she tends to leave her door open, so I know it'll get pretty messy, then she cleans it on like Thursday or Friday each week.
Also, because it's so recent, I haven't seen the affects on the bills yet.. And I just had a guy move in to the other room about 3 weeks ago. I'm afraid she's going to say that the increase is due to having 2 recent people move in.. I really cannot afford to lose anyone here. It's a nightmare to try and get a roommate that will stay, and I know if I was in someone else's place, and suddenly I was responsible for anymore money like utilities, I'd feel like I was being ripped off and start looking for another place.. However, I do like the limiting laundry to a couple of times per week, and putting it in writing. If I just say we've talked about it, and after an increase on the bill, we've decided it'd be best.. That way it's not attacking.. Funny how I never thought of that.. so simple...
Thanks you guys! :)