On your own lawn, just frowned on by the neighbors. On public property, like a park or a city street, I think it’s against the law.
BTW, I think we should keep in mind that this isn’t a question of just letting one person use laundry water on their lawn. That would most likely have a negligible effect. But if a community allows one person to do it, to be fair they must allow everyone in the community to do it. That would have a much greater impact on community health and the environment.
And watering the garden, as well? The garden that you work in with bare hands? The lawn that your kids walk on with bare feet.
Now don’t get me wrong, 99.999% of the time, it’s not a big deal. I doubt I’d have any problem with using gray water on my lawn. But it’s not the job of the local water dept. (which is what we’re arguing about) to have to worry about that rare occasion where you have a typhoid or hepatitis carrier in the household. The rule may be overcautious, but it’s not stupid.
And yeah, Manny, I guess phosphates could be a problem too, although it’s been a long time since I’ve seen laundry detergents with phosphates in them.
Only reason I’m beating this (by now, mostly skeletonized) horse is that it’s sort of annoying to have people be so dismissive about possible bacterial contamination. The only reason we can be so blase about it nowadays is that the combination of good sanitation and antibiotics has made the truly awful diseases like typhoid and cholera much, much rarer than they were. But as the recent outbreaks of e coli contamination have shown, we shouldn’t get too complacent.
What you guys need is a dual-flush toilet. These are compulsory installations in every new building in Australia. You have two buttons on top of the cistern; one allows a complete flush and the other drains only half of the cistern. It’s a neat solution in a country where water is a limited resource.
And incidentally, all our toilets have 1.5 gallon cisterns, for the same reason.