Solution for low-flow city water?

[mclark]

Hi, plumbing gurus.

My city house is fed by 1/2" galvanized steel, and the static pressure is 30psi but the flow is low, so a toilet flush reduces a shower to a trickle. I've replaced all house pipes by 3/4" copper from the water meter myself.

I've received quotes of >$10K to replace the city line (eeek!). Question: could my problem be solved by adding a captive air tank after my meter? My meter is in the basement of my two-story house.

Other considerations: Would I need an auxiliary pump? Do I need a backflow valve? What size tank - is 85gal enough?

Thanks in advance for advice - this solution could save me a lot of money since I can probably put this in myself for <$500.

[hj]

If the line to the meter is only 1/2", which is almost incomprehensible, and it is the cause of the pressure loss, then a well type storage tank in the basement, will give you a degree of relief, but a pump would be worthless because the 1/2" line could not supply it with adequate water and the pump would destroy itself.

[Cass]

That 1/2" Galv. line will fail sooner or later, it's just a matter of when. When it does you will have to replace it and then all the equipment you bought will be for nought. I would keep getting estimates and replace the line. If you offer Green Cash upon completion you may get lower estimates. How far are you from the street? $10K seems high, but I don't know the circumstances.

[FloridaOrange]

If the line to the meter is only 1/2", which is almost incomprehensible, and it is the cause of the pressure loss, then a well type storage tank in the basement, will give you a degree of relief, but a pump would be worthless because the 1/2" line could not supply it with adequate water and the pump would destroy itself.

1/2" supply??

[Cass]

1/2" supply??

Sure, 1000 years ago when it was put in the guy saved $10.00 by having the contractor use 1/2" galv. instead of 3/4".

He was cheap. :D

[FloridaOrange]

I guess the $10 was a big saving 1000 years ago ;) .
I'm relatively inexperienced (compared to master plumbers and such) and I learn more every day. Just curious then (and a little off topic), what is the actual meter size then? Here - a 3/4" 2 bath house supply typically runs through a 5/8" meter.

[mclark]

Here's the situation I inherited with this house: the pipe from the water main in the street to the curbside (about 12 feet in length) pre-dates records for my city (Ithaca, New York). The city water engineers believe that this line is 1/2" lead, but assure me that the lead poses no hazard of leaching since it has been 100 years. I found newspaper insulation around some pipes during renovation that date from 1904 (Russo-Japanese War headlines). The city charges to replace this pipe, and would NOT give a cost commitment; I have to sign a blank contract (!); they probably will charge $2-$5K.

From the curb to the meter is about 90 feet of 1/2" galvanized steel, but runs near a tree, under a brick pavement, next to my natural gas line, and we only have three feet of property along either sides of the house (crawl space in front-half, basement in original 1850 back-half). Excavation estimate: $7K; plumber estimate: $1K for hookup.

The house water meter is 3/4", and was replaced after it cracked during a freeze from winter foundation work a few years back (tough renovation - don't ask!).

Yes, this may be a "pay now or pay later" for the galvanized steel line replacement, but I honestly don't have the funds for $10K+. An 85-gal captive air tank from Sears is $300, and I can install it myself.

hj, you seem pretty knowledgeable. Would an 85-gal captive air tank (with no pump) be enough for say a 2nd-floor shower and accompanying toilet flush? I'm no expert, but my intuition is that this solution should work for 99% of my needs since most double-uses of water in my house are for short needs like toilets.

And thanks again for the comments, folks.

[speedbump]

Hi Mclark,

An 80 gallon (I assume your referring to an 80 gallon equivalent) bladder tank holds 9.9 gallons between 30 and 50 lbs. That's not much storage. The pump idea won't work just like HJ said, it will be starved for water it can't get. The biggest bladder tank made holds around 36 usable gallons of water. Then it's empty. If you have the room, a cistern is your best solution. Then you can go with a little 1/2hp jet pump and a flow switch or a tank.

bob...

[mclark]

Speedbump Bob,

I was thinking of this product:
Sears Craftsman 85 gal. Captive Air® Tank $299
http://www.sears.com/sr/javasr/product.do?pid=08329175000

The product specs say: Tank Drawdown at 30/50 PSI = 26

Do you think that this size tank would suffice?

Interesting enough, we uncovered a cistern next to our house under a slate slab during renovation - 14ft deep with 5ft of water in it. Also some steep pipes dropped in that I have no idea where they go! But I have no plans on using this. :^)

[speedbump]

I am not a fan of Sta Rite tanks. They make tanks for Sears, Home depot, Lowe's etc. And no I don't think this is a solution to your problems. As soon as the 26 gallons is gone your right back to what you had before.

You may want to reconsider renovating that old cistern. That would probably be your only permanent solution. Or a 200 to 500 gallon plastic tank somewhere in the house that can be used as a cistern with the jet pump and flow switch.

bob...

[Gary Swart]

When it was new, that pipe was too small. Now that it is old and corroded inside it probably is more like 1/4". Compounding the problem is the distance. You lose pressure from friction, and the smaller the pipe, the worse the effect. There is no way that this should cost the kind of money you are talking about. Here's what I'd suggest. Hire a couple of grunt laborers to dig the trench and fill it in after the job is finished. You sure don't want to pay plumbers to do this kind of work! When the trench is dug, then get a plumber to install a new 1" copper line. I say 1" because of the friction loss over 90+ feet. Some might advise 3/4", and that would work much better than what you have, but I like to oversize to give a margin for the future. There's no point in trying to cobble something together to allow continued use of that old pipe. It is overdue to start leaking, so you'd just be throwing money into a hole.