Cesspool or septic system? Design ideas?

[mella l]

Septic systems for lots under 1 acre presently and cesspools for lots over 1 acre. A county person told me that if our lot was 1 inch less than 1 acre we would need a septic system and leach field.

Think this is a great new topic. If I understood rightly, people want to know of others experiences, how it was designed, by whom, how deep this and that needs to be. How best to dig and prepare. Wish I were there to dig into this! Mella L

mella l

[Rob Tucker]

As an initial opening on cesspools and septic systems I would like to offer the following thoughts for consideration:

The lava soils here in Hawaii are extremely pourous. This has it's advantages and disadvantages. For waste treatment it means that, especially near the shore but inland as well, as our population increases the potential for polluted aquafir and beach waters can increase as well.

The costs of a cesspool vs. a septic system are actually quite similar, especially when compared to mainland expenses. The septic tank is the real difference here as the size of the septic field is not much different than the size of a cesspool.

The septic tank allows the wastes time to break down before flowing rapidly toward the ocean. And flow they will.

If it is within your budget please consider installing a septic tank whether or not you are on 1 acre more or less.

It is useful to remember when designing and planning your homes that the building codes are not telling you how to build your home - they are, and are only intended to be, the lowest standard allowed by law. Good judgement will often suggest that more care and effort be applied.

Chairman, Punaweb Committee, MSPA

[G. Leis]

Anyone have any experience with/opinion of these polyethylene septic tanks? http://www.chemtainerofhawaii.com/produc...spx?cid=31

aloha,
Gene

[Rob Tucker]

Well, I thought I'd hang back and let someone else step up to the plate on this. That not happening here's what I can tell you:

The poly tanks and/or possible fiberglas tanks are all that I have seen here over the past 10 years. On the mainland we used to use concrete tanks but if they exist on this island I am unaware off it.

My opinion of the poly tanks are that they are probably fine. I have installed them and know many others who have as well. Properly bedded (i.e. not with sharp rocks) I think they would do very well.

Minor notes:

Septic tanks are sized in Hawaii according to the number of bedrooms. 5 bedroom max. per septic system.

The price difference for a small tank (1-2 bedroom) vs. a large tank (5 bedroom) is so minor I think it a mistake to install anything but the larger tank. That way you have a potential to expand your home later without needing a new septic system.

Chairman, Punaweb Committee, MSPA

[G. Leis]

Thanks, Rob. The plastic tanks seemed like a pretty good deal to me.

This outfit http://www.jensenprecast.com/ makes concrete tanks and is headquartered on the mainland, but it looks as though they have some sort of facility in Honolulu. Maybe just a sales office and not manufacturing; kind of hard to tell from the website info.

aloha,
Gene

[HADave]

Do we know how large the average size system is in terms of excavation. Lets use a 3 bdrm home with a daily flow of approx 270 gallons. I thought I heard someone say that a cesspool has a cement cover. Here in Maine my system (drain field) takes up 900 sq ft that approx 20' x 40' They don't make cement covers that big , do they? The photos I've seen tend to suggest that cesspools are covered by a 4ft dia cover or so. Then again I might not understand how the cesspool is designed. I thought it was just a hole in the ground and the water drained out from there. Maybe someone could explain just how porous lava is and is all lava the same?

Dave

[Rob Tucker]

I would say that not all lava is necessarily the same but that the perc rate here is basically 100% with some rare exceptions.

A cesspool is your basic hole in the ground, usually 5'-6' in diameter with a concrete cover. The cover is commonly constructed by laying a few boards (or tree branches) across the hole, placing some old roofing metal on that, and then pouring concrete on the metal. A clean-out port must be made in the top also. Very primitive.

A leech pit will be needed for a septic system in addition to the septic tank. The fields can be quite small (10' x 10') - the size is determined by the septic engineer. The hole for the leech pit is filled with a properly sized cinder or other aggregate.

The rub here is that the county does not have simple, pre-approved, cesspool or septic plans. The systems they plan check and approve are all so much the same it would save everyone (except the engineers) a lot of time and money to have these basically predesigned.

Chairman, Punaweb Committee, MSPA

Edited by - Rob Tucker on 11/28/2005 19:45:36

[mella l]

As we wish to live as green as possible we will use the septic type system, even tho our lot size says that a cesspool will be allowed. Thanks for the info Rob, we will think ahead 20 years and be happy we went with the septic, and do our part to not pollute the shore, by doing the digesting type system!

mella l

[adias]

Aloha Mella,

When are you guys planing on building?



Ajit

[mella l]

Aloha Ajit,

We hope to put our home here on the market in February 2006 and be there as soon as we can! We have already microchipped the kitties, and there blood tests are in Kansas as I write! How about you and your family Ajit? When are you headed over?

mella l