10,000 gallon water tank delivered

saltman · Sep 5, 2007

Here in San Diego County it's madatory to have a 10,000 gallon water tank for fire protection if your house is over 1500 sq ft. I haven't started my house yet but had my water tank delivered today. The tank is 100 ft above my house pad in elevation and about 500 ft from the well. I will use my tank for drinking water as well as fire protection.

This is a large project and I have no exerience so give me your open suggestions since I know nada about plumbing or water projects.

Here is my plan. I will run a 1.5 inch supply line from my well to the tank using pvc schedule 40. I am having backhoe work done this weekend he is digging a 2 ft trench from the well to the tank. From the tank to the mandatory "fire hydrant" I have to run a 4 inch line which will also be PVC put in the same trench. The house is about 200 feet closer to the tank than the well is so the line (4 inch will run down the hill to the hydrant, then I will reduce it to 2 inch and run it to my house. I will have a shut off at the tank, the hydrant and my house. The well will have a ball valve at the well. Please pipe in with suggetions, things that come to my mind are water hammering, backflow prevention.

My house will be totally on solar and propane so I will have a propane generator that runs the well eventually but for now it's a gas unit. This is the reason I am running the well to the tank and then the house, with the well at 700 feet I need to use an electric well pump which is already in place.

I attached a few photos and will have more, these make the distance look greater than it is.

This is a true tractor/ backhoe project and, I'll have plenty of tractor photos since I am doing all of the back filling myself and this morning I leveled the tank location area.

Thanks

ps piping will be galvanized where exposed going into the well and tank.

MtnViewRanch · Sep 6, 2007

Saltman, are you sure that you are allowed to draw water out of your fire tank? I thought that these tanks were for fire only. If you were allowed to draw off of that tank and it was low, what good would it do for fire if it is 1/2 down or empty? Double check on the galvanized for the 4", it might need to be brass.

Just questions that I do not have the answers for. Where abouts is your property in San Diego County?

3RRL · Sep 6, 2007

Brian,
I don't know about San Diego County, but where I live we have to have the fire hydrant and a 4,000 gal minimum tank capacity. If your tank is larger than that, you can plumb your drinking/house water above the 4,000 gallon mark. My tank will be 5,000 gallons for that reason.
So your concern is a good one. Is 10,000 gallons the actual requirement for San Diego? Is the tank larger than 10,000 gallons? Otherwise Brian is probably correct.

TedLaRue · Sep 6, 2007

Your post may be "information overload", but I'll attempt a reply.

Edit: Sounds like MtnViewRanch and 3RRL have better advice than what I can offer. The concern about your fire reservoir also serving as your water supply is something to check in to.

Be sure the 4" line from the tank to the fire hydrant is SDR-35 or even Schedule 40 PVC. That's probably a code requirement. But fore-warned is fore-armed.

I installed a ball valve shut-off (brass) on my 1.5" supply line. Someone on a different forum several years ago warned me about using the ball valve, claiming that the shock of the sudden shutoff might cause excess pressure in the line before the shutoff. I've never had a problem, but I thought I should pass that on.

The public supply line is below the level of my property, and I have a long (1/2 mile) supply line, so I installed a check valve in the line. That way, if the public line develops a leak, it won't suck my line dry. The local meter reader suggested that. You wouldn't need this if you are at at or below the public water line.

Tororider · Sep 6, 2007

Wow, if you don't mind me asking, how much do they get for one of those? It would make a great tank for reclaiming rainwater for watering. Best of luck.

dfkrug · Sep 6, 2007

Nice looking tank. Is that stainless steel?

Anyway, in my over-regulated county (Santa Clara), some rural
residents are reqd to have 5000 gal, some 10000 gal. The fire
depts prefer that property owners take their domestic supply from
the same tank as fire use so the fire water does not stagnate. Two
independent tanks are allowed, however. Note that a 10000 gal
tank requires an engineered and inspected foundation, but 5000
gal or less is specifically exempted from reqd foundation permits in
the UBC (CA bldg code). Hence two 5000 gal tanks are sometimes
preferred over one 10000 gal unit.

My own concrete tank has a 4" sched 40 main, 500 ft long to my
brass "wharf hydrant". I pressure tested with air before covering
pipes in the trench.

saltman · Sep 6, 2007

Thanks for the responses. I did some reasearch today, apparently the county just passed a regulation in July 2007. It's a little vague and a lot of it seems to be up the to fire marshalls. The enitire thing is 72 pages.

I am not sure about using the tank for domestic water but the diagram they have shows the tank supply as domestic water and fire protection. I'll have to call them for a clarification. Worst case I will have to buy an additional say 1,000 gallon tank for my domestic use. The 10,000 gallon tank is galvanized and cost $4,250 dollars. Nobody out there (Jacumba Blvd area) has anything larger than a 10,000 gallon tank but I am sure some of the wells run directly to the homes.

I am in a catch 22 because I want to set the tank up and start using it for irrigation but don't want to be put in a position by the building department where I'll have to undo anything due to the fact that they want the tank to be for fire protection only. I don't want to spend another $4,200 for a big tank for irrigation knowing that this one just sits there full of water. I can always fill it at the end of a watering day for fire protection.

Should I put in a cement break (forget the technical name) to prevent water hammer where the pipe ends??

dfkrug · Sep 6, 2007

I do not see why you would get water hammer, after pipes are
purged of air. The initial fill can be dramatic, however, if you
fill the pipe quickly and the trench is still open.

MtnViewRanch · Sep 6, 2007

Saltman, what diameter is your tank? It looks to be 12' tall at the sides, but is it only 10' in diameter. If that is the case your a bit short on the 10,000 gallons. Your tank supplier might have brought out the wrong tank.

Just trying to give you a heads up before you have it plumbed in.

saltman · Sep 6, 2007

I'll measure it but am sure it's at least 12 feet across. It weighs over 3,400 pounds empty. It's been a while, can you give me the formula for volume, maybe I'll get lucky and it's larger! Most all the tanks here are the same size since the county requires they are either 5,000 or 10,000 gallons depending on your house size. Some of my neighbors have both and this is as large as theirs I am pretty sure, but I'll double check the measurements. The well guy fabricates these himself and gurantees them, so if it's not I can switch it out if he is willing to drive up the hill again that was a sight, they blew a tire going up and almost skid into each other coming down. It's funny but in a city like San Diego there are only a handful of well drillers.

Thanks