Water service sizing

[Kman1138]

Hi,

I'm trying to size a water service for a 2500 man camp. The Canadian National plumbing code does not calculate anything above 690 FU. I have 15,000 FU plus a full comerical kitchen plus a wet sprinkler system. How do I begin to calculate something this big?

Regards,
Kris.

 

[BigInch]

I'd start with 2500 p * 100 gal/day-pp / 24x60 + 10% = 200 USgpm for the potable system. The irrigation load, which will depend on the area to be irrigated that you don't mention does not have to be potable treated water, so that system I would think should be totally separate.

**********************
"The problem isn't finding the solution, its trying to get to the real question." BigInch

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[Kman1138]

I apologize, I should be clearer. The sprinkler system is for fire suppression. I think I will bring a separate 6” service for it. Wow 200 USgpm is a lot but the math looks good to me. Where did the 100 gal/day-person come from?

 

[cvg]

first, start by talking with the fire marshall to determine what the requirements will be for fire flow. That could easily be the controlling factor. If you can't provide a large enough service to provide sufficient fireflow, you may need to install a tank and possibly a pump system as well. This is a small town and for most small towns, you would have at least one day supply in the water tower. That would be a 250,000 gallon tank. Replenishing that tank overnite (12 hours) might require about 350 gpm.

 

[Kman1138]

Bringing the services to the site is not in my scope of work. I need to give them a size and usage and the client will do the rest. This camp is isolated in northern Alberta, i.e. oil & gas.

 

[BigInch]

Ya there's a tiny little bit of difference between fire sprinkler and irrigation sprinkler.

100 gpm/d-pp is a typical average usage figure per person.

Fortunately I found a reputable backup for that number,
-----------------------------------------------------------
(3) Q: How much water does the average person use at home per day?

A: Estimates vary, but each person uses about 80-100 gallons of water per day.
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FROM,

http://ga.water.usgs.gov/edu/qahome.html

**********************
"The problem isn't finding the solution, its trying to get to the real question." BigInch

http://virtualpipeline.spaces.live.com/

 

[cvg]

100 gallons/day per person is typically used in a residential setting. For a camp, things could be different and possibly less. For starters, how will laundry be done? If laundry is done commercially, off-site that could mean a serious reduction in the water usage. Similarly, what type of showers will be used? If they are low flow which typically installed in campsites, that may reduce flow. Toilets - are they plumbed or portolets? Also, what kind of diurnal curve will be expected? Are workers working one shift or multiple? Peaking factors need to be assumed for heavy use periods which can easily double the peak daily demands. Peak hourly demands could be as much as 3 - 4 times the avg daily demand.

 

[Kman1138]

From what I know, there will be two shifts. 1200 men per shift. Each man has his own room w/ lav, shower and water closet. There are 34 rooms per floor with three commerical washer & dryers per floor.

 

[BigInch]

Most residential water distribution systems have a laundry or two included in the area served, as well as a smattering of other light commercial establishments, restrauants, gas stations, car washes, etc. and nobody adds anything for those.

With 12/12 the use will result in a more balanced load than you would have in a typical residential neighborhood, so that's a very good feature of your particular demands. I wouldn't worry about anything else, other than the fire load. That will undoubtedly control the mainline sizes anyway.

**********************
"The problem isn't finding the solution, its trying to get to the real question." BigInch

http://virtualpipeline.spaces.live.com/

 

[cvg]

You need to compare peak flows with replenishment flows with fireflows. You need to check residual pressures for each. You need to meet all the design requirements including emergency supply. Hard to tell which will be the controlling factor for sizing your waterline.