We replumbed our old house when we renovated it and the plumbing system collects the gray water and disperses it on the roses. But the bathroom sinks go to the septic tank. But to answer your question, yes, I let the water run and most often collect it in a modified gallon jug that then sits on the toilet because we have the "new and greatly improved" toilets that flush with less water. What the govt didn't tell folks was that any lime on the inner porcelain from the water that slows the siphon even the least little bit, reduces the flush efficiency of the action. So that gallon is there to add to the bowl to make a flush that flushes. (And this is better than flushing it five times, just to get TP to go down.) Dave Barry, in Florida, has written of his misery with the improved toilets.

Regarding all these post on people making noise upstairs, I really need to post this. I bought a 2 bedroom condominium 8 years ago and the neighbor below me started complaining about noise I was making the 2nd day I moved in. He and his live in girlfriend complained that I made noise walking and moving furniture. The first few weeks I was really nice and put up with their crap. I was quiet after 9pm and I never play loud music and it was just me living here at the time. I went out of my way and did things I did not have to do such as not wash clothes, dishwater etc. I did this and put up with their complaints until this guy came up to my door after week 8 and began to complain because at 9:10 when i was readjusting my headboard the headboard feel and make a loud thump. (one noise and he runs upstairs) He also earlier told me it was his girlfriend that my noises bothered. When he came to my door after the headboard thumped I looked at my watch realizing it was not even 10pm and asked him if he realized it was not even 10. he then threatened to cause bodily harm to me and have other people do things to me etc. I told him to get off my porch or id call the police and to make a long story short, I had to get a restraining order on him. His girlfriend made him go to court to try to have the order not be placed and the Judge told him and his girlfriend they live in an apartment building (condo is the same thing) and he needs to complain to the builders not me. The judge granted my order and said he needs to expect to hear these noises of walking etc. So if you move in a bottom unit expect to hear people walking, washing machine going, dishwasher flowing, people getting out of bed in the morning and vacuuming etc etc. IF you don't like it then go rent or buy a house or live in an upper unit. I still live here and the freak below still tries once in a while to harass me but he has never come to my door and if he ever does it again my attorney is waiting so i can bring a suit against him. If yo move in a bottom unit you need to expect noises. Unless its later than 10pm you don't have much recourse.

Tools and procedure is actualy quite simple but mistakes or unexpected breaks while working on water supply can change things , ( think water turned off to intire house while searching for a plumber ). This is what I suspect is causing the noise. A loose washer in hot angle stop ( shut off valve where pipe exits wall beneath sink). 90% of the time this is the cause. The single valve can control facuet and dish washer both or there can be 1 valve for each. If each has a valve,turn the one for facuet off. Start washer and when noise starts adjust the valve for washer( slowly turn off and/or on. If adjusting valve stops noise, you can leave it in that position until your brother-in-law can come fix it or turn hot water off at heater or main supply to house. Open the offending valve about mid way then unscrew the cap between valve and it's knob/handle. When the threads come free of valve turn valve to full open and the stem handle assembly will fall free. The screw holding washer will not be tight if my hunch is correct. You can install a new washer or just tighten the screw. Lub stem and cap with silicon grease,WD40 or the like. On reassembly,screw stem in about half way then thread cap on and snug it a little more than finger tight. Turn valve off and restore water supply. Have wrench ready to tighten cap and turn valve on. The valve will likly leak between cap and stem. Slowly tighten cap until leak/drip stops. You can't buy parts for the valve so don't overtighten and bust the cap. If the leak doesn't stop without overtightening,remove the stem again and take it to the local hardware so the clerk can help you with correct packing. If adjusting the angle stop fails to quite the noise don't take it apart,post back and we will look elsewhere.

Any time I have a water system noise issue I will let the noise start and then sequentially turn off each fixtures supply valve until the noise stops. That tells me which fixture is the problem.