Catchment costs?

[Tink]

I believe the tank is exempt due to height/diameter ratio, but the electrical and plumbing portion of it requires permit according to amended exempt from permit requirements in the IBC. (IBC tank size is limited to less than 5k gallons, believe County amendment on this, they may treat it as an above ground swimming pool and not a water tank, therefore debatable interpretation of the Code).

Community begins with Aloha

[Jay Bondesen]

In my case the electrical is all off the shelf stuff and just plugged into a wall outlet in the garage so no special wiring although there is a dedicated plug/circuit for the pump. The plumbing run out from the house is part of the plumbing permit I think but I'm not so sure about the package connecting the tank, pump, filters, and UV system.

Jay

[kalakoa]

they may treat it as an above ground swimming pool and not a water tank

Yes: Code is unclear, but the setbacks and height limits would both apply, with additional requirements depending on whether the water is "potable" or "non-potable", and of course a backflow prevention device if County water is also available at the location.

Why, it's almost like they want you to need a licensed professional, or at least a consultant.

[Peter Epperson]

The building dept told me that any tank even a 4' tall doughboy, which should be exempted because they are less than 6' high, require a permit. It is a fuzzy area though. Are portable tanks that can be picked up and moved exempt? If you ask the county they'll say no but I'm not sure they're right about that. If you build an in-ground swimming pool it can be placed right up to the property line with no worry about the setbacks. But the county won't allow the same for a buried concrete catchment tank. And they can't tell me why.

It is an interesting situation with catchment. The county is very concerned with certain safety issues like stair design or handrails but when it comes to your water supply there aren't any standards for safe drinking water. I am impressed by the resilience of peoples immune systems. I've seen dead rats and even cats in peoples tanks that the owners were unaware of. In some cases they had been drinking the water with no filtration at all. They all appeared to be healthy functioning humans. I think Puna people may have exceptional immune systems from years on introducing microbes.

[MarkP]

There is some thought that increasing prevalence of childhood asthma is linked to an over emphasis on cleanliness and over use of anti-bacterial products. In other words the kids may not be getting properly inoculated with germs and their immune systems are not getting primed right. On the other hand given exposure to germs a certain percentage of people, kids in particular, will get sick and even die. So yes, Puna residents on catchment DO have especially robust immune systems due to their exposure to what is in the water systems. At least they should according to standard immune system theory. Undoubtedly some also pay the price. Just how big a price that is I don't know. I don't imagine many people actually die because that would stand out and get noticed. I think the greatest risk with having a carelessly maintained system is not the day to day load of germs but the potential exposure to a catastrophic event like the dead animal in the tank or a colonization of your roof by rats.

[VancouverIslander]

I think the hookup from the tank to the house comes under the plumbing permit, but the tank itself and connection from the gutters to the tank seem to be either part of the construction permit for the house or outside the process. Easy enough to call the county for clarification (probably faster to just go down to Hilo in person and ask, though, phones often take a long time to answer or get call back on in my experience), or just ask your installer if you go that way.

[Guest]

Be sure to run a pipe from the catchment water inlet (almost) to the bottom of your tank. That way, the freshest water in the tank will be at the bottom where your inlet is and the tank will naturally 'flush' itself when it rains via your overflow. If you do not do this, you are drinking stagnant water and the fresh rainwater simply runs out your overflow. I did this on my system and it works like a champ, even during downpours. The people who installed my system said this would never work and refused to install the pipe, so I had to do it myself. They had no background in engineering or hydraulic systems, I do. Or did, before I retired.

It works. After a heavy rain, you are drinking fresh water that is visibly clearer if you look in the tank.

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You can't fix Samsara.

[john the architect]

I have had great success with roof washer cleaned, ICF-tank stored, and UV-purifed water to shock people when they see you drink it. Next system I will specify will probably be Peter's, just structural cement and steel, higher upfront but lower maintenance costs.

John Maloney
310.562.0362
johnmaloney3@me.com
Hawaii Architect AR8082

[terracore]

quote:

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Originally posted by imagtek

Be sure to run a pipe from the catchment water inlet (almost) to the bottom of your tank. That way, the freshest water in the tank will be at the bottom where your inlet is and the tank will naturally 'flush' itself when it rains via your overflow. If you do not do this, you are drinking stagnant water and the fresh rainwater simply runs out your overflow. I did this on my system and it works like a champ, even during downpours. The people who installed my system said this would never work and refused to install the pipe, so I had to do it myself. They had no background in engineering or hydraulic systems, I do. Or did, before I retired.

It works. After a heavy rain, you are drinking fresh water that is visibly clearer if you look in the tank.

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You can't fix Samsara.

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Forgive me if this is a stupid question, but I'm just trying to understand the science of this.

If the water dumps downwards into the top of one side of the tank, and the overflow goes out the top of the other side of the tank, the water being dumped into the tank is already flowing downwards, (because of gravity) isn't the fresh water being directed towards the bottom of the tank by design? If that is true, the fresher water continues its journey towards the bottom of the tank, forcing the older water towards the surface, where the overflow kicks it out of the tank on the other side?

Unless I'm missing something, the only thing missing in both examples is a length of pipe? Having a pipe going to the bottom could cause some back pressure meaning it takes longer for your gutters to drain, allowing more contaminants to get in, causing the reverse result of what you are saying?

[MarkP]

I believe the goal is to introduce the water from the roof, which is considered dirty, to the bottom of the tank using a diffuser such that there is as slow and smooth an upward flow as possible. This results in settling out of anything that will sink. Consequently the water at the top is freer of settleable material than the water at the bottom is. This is only true if the water is introduced gently. You don't want "circulation" or for the water to leave the downspout with any appreciable velocity. It only winds up going up because there is no more room at the bottom, not because it got fired in that direction. Various diffuser designs attempt to achieve this effect. If it s working right there will be a layer of dirt on the bottom. If that dirt gets scoured up during a rainstorm you have not achieved the desired effect.

Why is this good? Only because you have a floating suction intake that draws water from just below the surface. It's a package deal.