Chemistry disposal? What do folks actually do with spent chemistry?

Aurum · Feb 1, 2009

Backflow prevention isn't expensive. Its usually a one way valve that you plumb into the mains water supply, or into the tap supply in the darkroom.

An inline valve, maybe £10 - 20 tops, plus the cost to fit it.

I have a tap designed to attach a garden hosepipe on the outside of the house. When I fitted it, it had backflow prevention built in, which is basically a fine nylon mesh filter fitted with a plastic disc valve. Actual manufacturing cost? pennies at most

removed account4 · Feb 1, 2009

tim and arum

i just realized i have a backflow prevention device
on the silcocks ( outside faucets for us americans )
it looks like this ...
they are not expensive - i always thought they just released pressure
( back pressure ) i never put 2 and 2 together and realized they were a backflow device.

thanks

john

tim_walls · Feb 1, 2009

jnanian said:
tim and arum

i just realized i have a backflow prevention device
on the silcocks ( outside faucets for us americans )
it looks like this ...
they are not expensive - i always thought they just released pressure
( back pressure ) i never put 2 and 2 together and realized they were a backflow device.

Indeed; backflow devices are all over the plumbing on your house .

To slightly go back to jgcull's question... Have you ever noticed you never see a tap and sink arrangement where the bottom of the tap is below the the overflow outlet? That's a mandated-by-code backflow prevention device: it should be impossible for the waste water in the sink to back up over the tap.

Similarly, the overflow pipe on the cistern on a toilet as described earlier is a backflow prevention device. Where the cistern overflow doesn't go directly 'to air' - i.e. it's piped away to a drain - there should be a tundish installed - basically a pipe-and-funnel arranged so the pipe pours into the funnel - so that if there is a blockage further down the piping it can't back up all the way to the cistern overflow (a tundish is another simple anti-backflow device.)

Basically, any piece of plumbing built to any sensible code should already have anti-backflow prevention built in; I've included it in my darkroom wet-side designs. It's a standard part of any plumbing design/installation. I'm not sure why in Toronto they feel the need to single out film processing installations for special treatment, but maybe they're just applying belt and braces.

wogster · Feb 1, 2009

tim_walls said:
Indeed; backflow devices are all over the plumbing on your house .

To slightly go back to jgcull's question... Have you ever noticed you never see a tap and sink arrangement where the bottom of the tap is below the the overflow outlet? That's a mandated-by-code backflow prevention device: it should be impossible for the waste water in the sink to back up over the tap.

Similarly, the overflow pipe on the cistern on a toilet as described earlier is a backflow prevention device. Where the cistern overflow doesn't go directly 'to air' - i.e. it's piped away to a drain - there should be a tundish installed - basically a pipe-and-funnel arranged so the pipe pours into the funnel - so that if there is a blockage further down the piping it can't back up all the way to the cistern overflow (a tundish is another simple anti-backflow device.)

Basically, any piece of plumbing built to any sensible code should already have anti-backflow prevention built in; I've included it in my darkroom wet-side designs. It's a standard part of any plumbing design/installation. I'm not sure why in Toronto they feel the need to single out film processing installations for special treatment, but maybe they're just applying belt and braces.

It's probably because of machine processing, where the machine may be directly attached to the water supply and come from somewhere outside the country where such devices are not needed or used inside. Would seem to make more sense to mandate that backflow devices be installed between such devices and the water supply. However this is Toronto, and Toronto tends to over react on everything.

Bob Carnie · Feb 1, 2009

Page 1 and 2 from a pamphlet left behind.
at least I hope they show up as attachments

removed account4 · Feb 1, 2009

years ago there was an episode of quincy, yeah the cheesy american forensic pathologist show ..
anyhow there was a kid who had come down with some crazy illness and jack ( klugman ) had
to figure out what happened so others didn't get sick as well.
more and more people were getting sick as the 1 hour show progressed .. what he learned was that there
was a water fountain ( a bubblah for those in ri ) whose drain was clogged and nasty foul water was
in the drain basin. there was a hose that was standing in the water going back into the water supply ...
and obviously no back flow prevention device .. because the fetid water syphoned back into the system
and got people sick.

it doesn't seem the folks in toronto are over reacting because if a hose attached to a faucet isn't drained
and sitting in a pool of water that is contaminated with photochemicals ... and there is back pressure on the pipes,
the contaminated water can be slurped back into the water supply.
may be that only happens in LA.

tim_walls · Feb 1, 2009

jnanian said:
it doesn't seem the folks in toronto are over reacting because if a hose attached to a faucet isn't drained
and sitting in a pool of water that is contaminated with photochemicals ... and there is back pressure on the pipes,
the contaminated water can be slurped back into the water supply.
may be that only happens in LA.

Hah, I love Quincy.

I don't think they're overreacting. What I do think is this: If there is a darkroom out there that doesn't have appropriate backflow protection in their plumbing then they should (a) have never been allowed to open their doors in the first place, (b) should be closed down immediately, (c) should have already been in breach of existing building code.

Which is why it seems odd that they bring it up now as some kind of new requirement. Like I say, I suspect it's belt and braces - if they demand a single backflow protection device at the inlet, then it saves them the trouble of actually having to inspect the plumbing inside to make sure it was up to code.

(I see from Bob's pamphlet this makes sense, although the text is too small to read the body - it appears it's aimed at all industrial users and multi-residential properties; i.e. establishments where the plumbing is likely to be either (a) complex, and so hard to vet, and/or (b) potentially difficult to access if/when vetting is required. A simple double check valve at the common inlet is a much easier thing to check than making sure every bathroom in a block of flats is up to code, or every sink and film processor in a darkroom has been correctly fitted.)

Bob Carnie · Feb 1, 2009

Hi Tim

I think you hit it on the head, this inspector was very adamant that the backflows were at the buildings main water entry point just after the main meter with absolutely no plumbing attachments between the meter and backflow device. He indicated that trying to isolate every potential sink, drain in a building would be impossible to moniter , but a quick look at the main entry point would be easy for his inspection team.
The logic was to isolate the building from the communities water supply . Apparently a water main break, Emergency Fire requiring usage of water can create a drop in pressure enough for buildings surrounding the emergency not backflowing into the citys main water line.
Apparently these devices are not crazy expensive but I would think the bill from the Steam Fitter/Plumber would be no laughing matter.

Just to add one more note. This inspection is not only aimed at photographic operations , but all kinds of industrys and buildings that work with products that may not be wise to mix with our main water systems.
He was even mentioning Dentist Offices using xray devices and process.

tim_walls said:
Hah, I love Quincy.

I don't think they're overreacting. What I do think is this: If there is a darkroom out there that doesn't have appropriate backflow protection in their plumbing then they should (a) have never been allowed to open their doors in the first place, (b) should be closed down immediately, (c) should have already been in breach of existing building code.

Which is why it seems odd that they bring it up now as some kind of new requirement. Like I say, I suspect it's belt and braces - if they demand a single backflow protection device at the inlet, then it saves them the trouble of actually having to inspect the plumbing inside to make sure it was up to code.

(I see from Bob's pamphlet this makes sense, although the text is too small to read the body - it appears it's aimed at all industrial users and multi-residential properties; i.e. establishments where the plumbing is likely to be either (a) complex, and so hard to vet, and/or (b) potentially difficult to access if/when vetting is required. A simple double check valve at the common inlet is a much easier thing to check than making sure every bathroom in a block of flats is up to code, or every sink and film processor in a darkroom has been correctly fitted.)

wogster · Feb 1, 2009

jnanian said:
years ago there was an episode of quincy, yeah the cheesy american forensic pathologist show ..
anyhow there was a kid who had come down with some crazy illness and jack ( klugman ) had
to figure out what happened so others didn't get sick as well.
more and more people were getting sick as the 1 hour show progressed .. what he learned was that there
was a water fountain ( a bubblah for those in ri ) whose drain was clogged and nasty foul water was
in the drain basin. there was a hose that was standing in the water going back into the water supply ...
and obviously no back flow prevention device .. because the fetid water syphoned back into the system
and got people sick.

it doesn't seem the folks in toronto are over reacting because if a hose attached to a faucet isn't drained
and sitting in a pool of water that is contaminated with photochemicals ... and there is back pressure on the pipes,
the contaminated water can be slurped back into the water supply.
may be that only happens in LA.

This would apply to just about any device that is connected to a water supply, I can think of much more dangerous stuff then photo chemicals, even in a residential setting. Really there should be such a back flow device in every water mains supply, right beside the meter. I live in a house and there is no back flow device on the water supply.

Bob Carnie · Feb 2, 2009

Paul
After talking to this inspector , I would not be doubt that a back flow device will be Mandatory in all buildings in the GTA. Now I just have to start the fight/negotiations with my Landlord about this building.

wogster said:
This would apply to just about any device that is connected to a water supply, I can think of much more dangerous stuff then photo chemicals, even in a residential setting. Really there should be such a back flow device in every water mains supply, right beside the meter. I live in a house and there is no back flow device on the water supply.

wogster · Feb 2, 2009

Bob Carnie said:
Paul
After talking to this inspector , I would not be doubt that a back flow device will be Mandatory in all buildings in the GTA. Now I just have to start the fight/negotiations with my Landlord about this building.

What you may want to do, is talk to a plumber, if it's say under $200, it's often easier to simply do it, and then, send the landlord a letter with a copy of the bill enclosed, if you get it back, that's a good thing, if not, write it off as a cost of doing business.

I can't see it being that expensive, cut the pipe fit the back-flow device (maybe $10) and solder it in, probably an hour of the plumbers time, nice thing is, you can largely control when your water will be off for the installation. It's certainly cheaper then getting shut down by the city, until you get it fixed, along with a nasty fine and the fact that the inspectors not going to hurry back to check the work, to let you reopen the lab. They will probably pick the busiest season to shut you down, costing many thousands of dollars in lost business, and customer loyalty.

Bob Carnie · Feb 3, 2009

I am thinking the job is a bit more than a couple of hundred bucks, the line coming into the building is huge and not copper but some kind of cast metal pipe, I am thinking a steam fitter is in order.

wogster said:
What you may want to do, is talk to a plumber, if it's say under $200, it's often easier to simply do it, and then, send the landlord a letter with a copy of the bill enclosed, if you get it back, that's a good thing, if not, write it off as a cost of doing business.

I can't see it being that expensive, cut the pipe fit the back-flow device (maybe $10) and solder it in, probably an hour of the plumbers time, nice thing is, you can largely control when your water will be off for the installation. It's certainly cheaper then getting shut down by the city, until you get it fixed, along with a nasty fine and the fact that the inspectors not going to hurry back to check the work, to let you reopen the lab. They will probably pick the busiest season to shut you down, costing many thousands of dollars in lost business, and customer loyalty.

Chemistry disposal? What do folks actually do with spent chemistry?

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