Lead free plumbing fittings?
We replaced the lead supply water supply line to our house 2 years ago after we discovered that due to high acidity in the city water, unsafe levels of lead were leaching.
Now my wife is paranoid about lead (the lead leaching occured exactly during her pregnancy with our two kids so I don’t blame her). She tests regularly and every tap shows 0 ppm of Pb (I replumbed everything with no-Pb solder too) EXCEPT for our fridge door water dispenser which shows a small (below “safe” levels) amount of Pb.
I suspect that the brass fitting that connects the 1/2″ copper pipe to the 1/4″ (I think) flexible copper line to the fridge.
My question is: Where can I find a no-lead fitting for this? I’ve searched the web for hours and cannnot find anything. I’m tempted to draw one with CAD software and send it off to a machine shop to have milled out of stainless but am sure that would cost at least $150.
P.S. The city traced the problem to a combination of “biofilm” (algae growing inside the water main adding acid to the water) and a situation in our neighbourhood where low flow volume was occuring (we are at a dead end of the main) which resulted in lack of flushing of the acid.
It's probably just that the water sits in the copper pipe too long. Run a gallon or so of water out of the thing every day for a week and then remeasure.
If you're really serious, have a look at Parker or Swagelok compression fittings. They'd (more than) do the job, and you have your choice of stainless steel or brass. Contact either of them and they'll tell you the composition of their brass, including any lead content. But I'd be surprised if a single brass fitting was contributing a measurable amount of lead.
I agree with the flushing. Remember when your parents told you not to run the water so long (to wait for it to get cold) before you filled a glass to drink? They were wrong. Run the water until it's cold- then you're sure you're getting more or less what the city supplies you with, rather than the water that's been hanging around in your pipes for hours (or days...). But the city's piping won't be scrupulously lead-free either. Clearly it's a lot harder to get to and more expensive to replace than your home plumbing...
Really worried about lead? Drink from a Brita-type filter. But make sure you change the filters monthly and keep it in the fridge when you're not using it. Otherwise you'll be running the risk of drinking microorganisms which may be worse for you than the lead.
Almost all true. Swagelock would certainly have it in SS. There may also be brass fittings inside the fridge that opens and closes for water flow and to the ice maker.
But while plate counts of bacteria increase with a carbon filter, those are not pathological organisms that cause disease. But yes, changing the filter monthly helps keeps those critter counts down.
David Thomas Overlooking Cook Inlet in Kenai, Alaska
David: Drinking water from which the chlorine has been removed (i.e. Brita water) should be kept refrigerated or in sealed containers. Pathogens can come from anywhere, especially if you have a few little germ magnets running around. Activated carbon, even with a little silver on it as a biocide, is a pretty good home for bugs to grow.
As to whether or not a Brita removes lead, the ion exchange resin mixed in with the activated carbon does a decent job. Even the carbon itself does some of the work. Not perfect, mind you, and no good once its sorption capacity is exceeded- that can be pretty quick if you've got other metals in the water. Don't know what the problem was with the other poster's tests, but it's one anecdote against a fair bit of product testing.
Good on ye to think of the fittings inside the 'fridge itself. You're probably right- it's entirely possible that they're leaded brass just like the HD throwaway that's the current suspect. Last I checked, fridge water and ice systems weren't NSF certified devices...
As to soldering the stainless Swagelok fitting, absolutely not. You could silver braze it on, but I wouldn't recommend it. The right silver braze will stick to stainless, and to copper, but it's unnecessary in this case. At water system pressures, even stainless ferrules should swage well enough on copper tubing- though our normal practice here would be to replace the ferrules with brass when swaging a stainless fitting to copper tubing. Good rule of thumb when mixing materials with compression fittings: the ferrules should match the tubing, and the fitting should match the stronger of the two tube materials. In this case, if you can get away with brass ferrules, you can get away with a brass fitting (and that would be about 1/5 the cost of the stainless one for typical Swagelok stuff).
Agreed, carbon (Brita) has some adsorbtive capacity for lead (arsenic too). Not much, but the concentrations are very low.
A given: bacteria can live on carbon. I've used that fact many times in treatment systems.
Take home question: But if filtering chlorinated water, does the chlorine adorbed on the carbon prevent biogrowth? Or is the downstream carbon, not yet full of chlorine, good real estate for growing bugs?
This is the Fine Chemical Engineering forum, isn't it?
David Thomas Overlooking Cook Inlet in Kenai, Alaska
Speaking of filters, many fridges have a built-in water filter. It may be contaminated with lead and should be changed.
Thanks everyone. I'll check out the suppliers mentioned for SS fittings.
By the way, Britta filters don't remove significant amounts of lead from water. When we discovered the problem, the city sent a person once a week for almost a year to measure the lead in our water. They tested various taps as well as our Britta jug. There was no drop in the Pb count from the Britta.
In the end, the only thing that worked was replacing the lead supply line out to the main ($7000 job!). The city also installed a alkalining system in our neighbourhood to keep the pH up in order to reduce leaching.
>>But I'd be surprised if a single brass fitting was contributing a measurable amount of lead.
It does seem surprising but I can't explain it any other way. The filter was changed after we replaced our main supply line and the other taps in the house were tested and showed unmeasurable (0) amounts of lead.
I wonder if maybe the fitting I used is made of el-cheapo brass with high lead content. I bought it at HD.
I checked out swagelok and found what I needed. Can I just solder the SS fitting to Cu pipe. Won't galvanic corrosion result?
You can't solder SS to anything.
How much lead is given off during the life of the fitting(s)? Do you think it will make a difference? Did you know that one of chemical/mineral components that they feel helps Alzheimers along is aluminum????? Next time you rub/spray/wipe your arm pits, read the ingredients!!!! Also, sitting in traffic, do all those hydrocarbons help there as well??
Being cautious is one thing using solid copper fittings, M or L tube and lead free solder, what other precautions can you think of....CPVC plastic water pipe??????
>> How much lead is given off during the life of the fitting(s)? Do you think it will make a difference?
After drinking water with 4x the safe levels of Pb for up to 6 years, we're kinda paranoid. With two young kids in the house we want to reduce lead as much as possible.
>> Did you know that one of chemical/mineral components that they feel helps Alzheimers along is aluminum?????
Ya. I stopped using deodorant years ago. Lost all my friends though ;)
It could be that the lead from the lead pipe deposited a film inside your plumbing, and it's very slowly dissolving back into the water. High lead can certainly be a hazard, but if you're testing consistently zero or extremely low levels, forget about it and get on with life.
You may be able to assuage your fears by testing the blood lead level of someone in your family. If there's no elevated level, again, there is no problem other than worry.
Have you replaced the copper tubing feeding the fridge? It may be coated with lead on the inside.