Septic Vs Well Water

[HeijoshinCool]

Why do they place the septic tanks just a few feet away from the well hole?

I've seen this many a time and wonder if there is something I'm not seeing that's different about Thai septic tanks. Do they vaporize the waste? (joking) Seems, actually, they are far less efficient due to the lack of adrain fields.

Question 2: Anybody here installed a drain field?

[splitlid]

are you sure its not a soak away? overflow from septic tank flows into soakaway,also for grey water.

[HeijoshinCool]

are you sure its not a soak away? overflow from septic tank flows into soakaway,also for grey water.

Not sure. I can guess what a soak away is, but please describe what I should look for. Under or above ground?

[splitlid]

concrete rings buried in the ground.

[kamalabob2]

Proper Septic Tanks are not expensive if bought at the right independent builders merchant who specialize in water pumps, water tanks and PVC. Every province in Thailand has such shops which often have staff who have attended Thailand Technical Colleges and they can draw up proper plans to work with even "Village Builders" so that "french drains" with proper Perforated thick walled PVC into a septic drain field AWAY from wells. DOS markets high end septic tanks, but other brands which function exactly in the same manner are "Safe Brand" and "Trident". SLOPE SLOPE SLOPE is the mantra a smart septic installation team, I initially had otherwise. This year we had our septic drain pipes changed, our rain water from roof rain gutter downspouts changed to a much better sloped situation. The one shower drain that did not have a "U" trap under the house was changed and WOW, that smell is gone. Simple stuff the original builder let slip by. Common, but true experience in Thailand.

This brand of either Polyethylene or fiberglass septic tanks come with the "bio-media" and hose pipe to be installed anywhere in Thailand and not at Mall Store prices.

http://www.safefiberglasstank.com The site is in Thai, but you can see enough of the specs so that a shop owner who speaks and understands English can show you brochures of options for your septic tank needs. At a VERY fair price. The right shop giving you a plan in Thai so the typical construction workers can follow that plan and check for slope and use the proper stone, is crucial in my experience. Often the same shop will also sell Diamond Brand Stainless Steel tanks for the lowest price in the province and include free delivery and a fair price for professional installation. Many of these shops in Thailand have facebook pages and/or web sites so you can see in advance what they might sell, deliver and install, including drainage systems. I paid a fair price to Ruangsangthai in Buriram to dig out a previously poorly constructed drainage system, to fix drainage pipes under one bathroom and to see our rain water, leave the area near our house in a proper manner. Real plans, a total price per linear meter with exact parts listed, and it was tested each step of the way. This sort of inexpensive, yet professional service is not unique to this one store. Ask the successful Thai businessmen in your area where they buy septic tanks, water pumps and have the work done. typical store listing

http://www.facebook.com/pages/Buriram-Ruangsangthai-Ltd/503589409660852?fref=ts The right shops in your area will gladly send staff to YOUR home to look at your present water supply or septic drainage situation (or a new build situation) and then go back to the shop to draw up plans and give you written options BEFORE you send a single baht. This whole process, for a three bathroom home, including installation can be less money than one fair size air conditioner.

[NeverSure]

That would freak me out, as would not having the proper seal on the well casing. The well should be a minimum of 100 feet from any part of the septic system.

When the well is drilled, and let's say it is a 6" (15cm) hole, then a corresponding sized steel pipe should be driven into the hole to a depth of about 20' (7 meters.)

As the steel pipe is driven in by the well drilling machine, a thin cement should be poured around it as it goes in, creating a seal. The pipe should be left sticking up almost 2 feet (2/3 meter) above the ground to stop rain water from going into the well. They make seals for the top of the well pipe which will accommodate and seal the water pipe which goes into the well. Now nothing can get into that well from surface water, bugs, etc. etc.

If it would help, I will post a picture of mine, but it is dark out here now.

[NeverSure]

OK, here is a picture of a seal for the top of a well pipe. It is two steel halves, with a rubber seal in between. It is slipped into the top of the well and the bolts are tightened. as the bolts tighten, they pull the two white parts together, expanding the rubber in between and pressing into the sides of the pipe. Presto, seal. The center hole is for black flexible PVC which will be a press fit and then seal too. I have flexible black PVC all the way down to my pump and I love the idea. It is lightweight and flexible if I ever need to pull the pump. Compare that to 20' lengths of iron pipe, each threaded together to a depth of 300' (100 meters.)

http://www.ebay.com/itm/NEW-5-SANITARY-WATER-WELL-SEAL-1-1-4-DROP-PIPE-/380027227408

[HeijoshinCool]

concrete rings buried in the ground.

Okay, that's all there is, just delapidated 40 year old concrete compartments with ill-fitting tops. One is 2 meters from the well, the other is less than 3 meters.

So, my understanding is that the overflow just seeps out into the surrounding ground.

Wonder-<deleted>-ful!

[HeijoshinCool]

kalamabob and neversure, thanks. And for the links, too.

I have installed systems in the west, just wasn't sure about the concrete rings. All I've been told is there is no field with these. They're supposed to be pumped out from time to time. These are not. And that they leak -- intentionally.

dam_n. I have another 4 months in this house before I finish building the new one. Probably get Hepatitis before that.

[NeverSure]

kalamabob and neversure, thanks. And for the links, too.

I have installed systems in the west, just wasn't sure about the concrete rings. All I've been told is there is no field with these. They're supposed to be pumped out from time to time. These are not. And that they leak -- intentionally.

dam_n. I have another 4 months in this house before I finish building the new one. Probably get Hepatitis before that.

Actually the drain field on a proper septic system leaks intentionally too. The difference is that is usually has at least 3 leach lines spread over a much bigger area so that there is much more soil to absorb the effluent. Nature then breaks down that liquid into harmless soil nutrients.

Some problems that can arise are those such as a clay soil which isn't permeable, a very high water table which then won't allow the effluent to leach away, flooding, and eventually plugging up with solids and a need for pumping clean and hauling off.

If I had a really good permeable soil without the water problems, I wouldn't be as worried about the septic design as I would about the proximity to the well and perhaps the lack of a seal on the well.

Edit. My septic system is 7 1/2 years old and I haven't had to do anything to it. The solids including proper toilet paper will dissolve in the tank after settling to the bottom. The liquid runs into a pipe which is near the top of the tank, and that is the pipe to the drain field. It is lower in height in the tank than the pipe coming in from the house.

There are actually two tanks which I like. Each is 750 gallons (576,000 teaspoons.) OK, about 3 cm. The first gets effluent directly from the house. The solids settle to the bottom and begin to liquify. As that tank overflows, it run into the next tank and much smaller solids settle to the bottom. As that second tank overflows it then runs to the drain field. (leach lines)

Edited December 11, 2012 by NeverSure

[HeijoshinCool]

kalamabob and neversure, thanks. And for the links, too.

I have installed systems in the west, just wasn't sure about the concrete rings. All I've been told is there is no field with these. They're supposed to be pumped out from time to time. These are not. And that they leak -- intentionally.

dam_n. I have another 4 months in this house before I finish building the new one. Probably get Hepatitis before that.

Actually the drain field on a proper septic system leaks intentionally too. The difference is that is usually has at least 3 leach lines spread over a much bigger area so that there is much more soil to absorb the effluent. Nature then breaks down that liquid into harmless soil nutrients.

Some problems that can arise are those such as a clay soil which isn't permeable, a very high water table which then won't allow the effluent to leach away, flooding, and eventually plugging up with solids and a need for pumping clean and hauling off.

If I had a really good permeable soil without the water problems, I wouldn't be as worried about the septic design as I would about the proximity to the well and perhaps the lack of a seal on the well.

I will be installing a proper setup at the new house, but for now the concrete tanks are full of **it and leaking almost directly over the well head.

Amazingly, they have city water right there, but refuse to use it.

[NeverSure]

Is it that city water is expensive, or do they just not care?

[canopy]

I am going to pack this paragraph with everything a person with imagination needs to know. Drain fields are wonderful. With a drain field, 40% of waste treatment occurs after your septic tank. Drain fields are shallow and have plantings over them to draw out the nitrogen. The typical Thai system of a pit of concrete rings does not meet minimum international standards. There is no secondary treatment of waste and concentrated waste seeps down and pollutes ground water. Septic tanks should also be properly sized. The ones you see at the hardware store are too small which reduces treatment and need pumped out frequently. They are also single chamber which further reduces treatment and can leak because they are designed to be cheap, not good. For comparison sake, the building code of Florida which has a comparable climate requires a septic tank of 3400L or LARGER based on usage. Moral of the story is you are throwing away many would-be benefits when you reach for that 800L unit at the hardware store and outlet into some rings.

In my observation you can either have a septic system thrown together by a high school dropout builder who has absolutely no knowledge or care about designing a suitable system which is the norm where even simple things like pitching pipes, venting, and cleanouts are lost on them. Or you are on your own to put together a properly engineered, proven system like those in use worldwide that do not need pumped frequently, treat waste effectively, do not pollute the ground water, and have a host of other benefits you can enjoy reliably.

[NeverSure]

I am going to pack this paragraph with everything a person with imagination needs to know. Drain fields are wonderful. With a drain field, 40% of waste treatment occurs after your septic tank. Drain fields are shallow and have plantings over them to draw out the nitrogen. The typical Thai system of a pit of concrete rings does not meet minimum international standards. There is no secondary treatment of waste and concentrated waste seeps down and pollutes ground water. Septic tanks should also be properly sized. The ones you see at the hardware store are too small which reduces treatment and need pumped out frequently. They are also single chamber which further reduces treatment and can leak because they are designed to be cheap, not good. For comparison sake, the building code of Florida which has a comparable climate requires a septic tank of 3400L or LARGER based on usage. Moral of the story is you are throwing away many would-be benefits when you reach for that 800L unit at the hardware store and outlet into some rings.

In my observation you can either have a septic system thrown together by a high school dropout builder who has absolutely no knowledge or care about designing a suitable system which is the norm where even simple things like pitching pipes, venting, and cleanouts are lost on them. Or you are on your own to put together a properly engineered, proven system like those in use worldwide that do not need pumped frequently, treat waste effectively, do not pollute the ground water, and have a host of other benefits you can enjoy reliably.

Great post. Now, requirements vary due to soil types. Let's not forget that Florida has vast stretches of pure sand for "soil." It's the real soil which is decomposed organic matter which will really break down waste as the micro organisms work on it. Also in real soil, the effluent travels much slower in the drain field.

Oregon, which is known for being a leader in environmental causes, sizes septic tanks by number of bedrooms. I guess this is an indication of how many folks will be causing waste water. Something between 750 - 1,000 gallons is the norm, or 3,000 to 3,800 liters. You are right, in most cases the tank has two chambers with a demising wall in the middle. The effluent first flows into the first chamber and the solids drop to the bottom. As it fills liquids spills over the divider into the second chamber for further decomposition. From there the effluent enters the drain line which then splits into at least 3 perforated leach lines which are properly installed in ditches filled nearly to the top with round drain rock. This allows evaporation, and also leaching out into the soil where micro organisms clean the waste water to completely sanitary. The planting above the drain field could just be grass, but I opted for Vinca which is just more decorative and lower maintenance. You would not want to plant most trees over it as the roots would invade the perforated drain lines and plug them. It's bad enough to have to bore out the drain lines every decade or two as it is, if it happens.

Now, I have two septic tanks, one right after the other which complies with the need for two chambers. Each is 750 gallons for a total of about 6,000 liters but that was my choice. It does the same thing, meets code, but gives the effluent more room and more time for solids to dissolve.

Actually, the breaking down of solids including stools and toilet paper occurs in the septic tank and the purifying is done by the micro organisms in the soil in the drain field.

I don't know what size tanks they are selling where you mention and I have no doubt you are right because you know what you're talking about. The raw sewage needs enough room and enough time at the bottom of the tank to completely dissolve before entering the drain field. Obviously this is one more place where "size matters."

[HeijoshinCool]

Is it that city water is expensive, or do they just not care?

Maybe 200 per month.

And, they think I'm nuts about the well being next to the sh*t tanks.

The switch is bad on the pump, too. Doesn't sense pressure and runs forever. I offered to replace it if they buy a new one (300 baht). Oh, no! They walk outside, rain or shine, to plug or unplug it, while standing in ankle deep water.

[HeijoshinCool]

Thanks for the replies. You guys sure know your sh*t!

[canopy]

Now, requirements vary due to soil types.

First off, great response. And yes, all soil is different and these differences are important. A soil percolation test needs performed at the site and the results used to design a drain field; this test takes just a few minutes with some water, a measuring stick, and a timer. You don't have to have super special soil per se because the rock in the drainfield creates a large surface area for microbial biofilm communities to develop. I believe that no matter what type of soil you have, there is always a better system than the small septic tank & concrete rings which is just a glorified waste container polluting the environment.

[Beardog]

If your septic is built right it should last you 25- 30 years without ever needing a pump out. You need to use bleach duck or other cleaning agents sparingly if you have joing showers or sinks into your main leading to the septic. I like the concrete ring method as it actually adds up to 4 times the amount of useable area & is very easy to service if you ever had to. You need as said previously 30 meters from a well or borehole to insure clean drinkable water without having to worry about fecal matter contaminating your fresh water source. If you build your system- be it a premade or a ring settup you should never need any starter kit. just add shit. Use toilet paper sparingly & at all costs be nice to your septic system & don't kill off the natural enzymes that keep your septic working. Duck - draino type products & bleach are a septics worst nightmare.And lastly contrary to Thai belief you do need an adequate drainage field. Their are percolation tables you can use to determine what is adequate. 4-6 people drainage field 7 meters long X 1 meter deep X 55 centimeters wide. Guarenteed to last 25-30 years.

[extexthai]

On using the concrete rings...the proper installation of a sanitary tee will let the ring (if it has a bottom and has been plugged to hold effluent) form a scum layer. This is part of the septic cooties eating away what they think is delicious fare. The tee is attached to the inlet with the swoop going down and the other end straight up. I add a 20 - 30 cm piece to the bottom and then the same on the outlet. This allows the scum layer to form and not drain out and away. I had to use regular septic tanks (anaerobic microbes) along with secondary settling tanks and then an additional aerator tank (aerobic microbes) because of the hard-pan clay substrate we have here that allows for easy rice farming. Clay will not perk and drain fields are out of the question where I live. Water in...water out. The heavy stuff sinks to the bottom. I know, I know...some sh*t floats, but still.... If using secondary and tertiary tankage, the inlet of one is always higher (5-10 cm) than the outlet and it all has to have the proper slope or it won't work. Thias plumb the way they drive....no sense at all. I can't attach a photo to this or I would show it. I have posted on this before and you can see photos of my set up there. Good luck ett

[HeijoshinCool]

My conclusion is that a hybrid of Thai and western would be appropriate and functional. It's a small one bedroom house, never more than two occupants.

I now plan on running shower, sinks and laundry, as grey water, 50 meters into the rubber trees. Seldom use bleach, except washing, and don't see the harm to the environment. Certainly never have liked putting bleach and other cleansers in the tank.

As for the tanks, yes, western is excellent, but pricey. I'm thinking two sets of concrete rings, far away from the water source. First set is mortared, second set of rings drains into perforated pipe over gravel (we're building up a meter).

I have not seen the perforated pipe here. Anybody? That's a lot of drilling!

Lastly, does it make a difference, engineering-wise, if the volume of the tanks is made up of height (deep) as opposed to length?

[NeverSure]

I think that will work fine. The gray water is excellent fertilizer because soaps are high in nitrogen and other minerals. Someone actually wrote a funny book titled "The Grass Is Always Greener Over The Septic Tank." You might actually want to use a flexible hose that you could move some.

Bleach evaporates and breaks down so fast when mixed with water and exposed to air that it will hurt nothing. It does have time to kill bacteria when put into a septic tank in strong enough mixtures.

As for what's called "perf pipe" I don't know in LOS. Maybe someone else does. Just remember that nothing will work on the black water system if the water table reaches the level of the system. We can buy that perf pipe as black flexible pipe in rolls and it's cheap. If it is surrounded by drain rock (non crushed, round rock about 1" (25mm) in diameter and about 2" (2/3 meter) deep, it won't crush. The drain rock must be surrounded by fabric which allows water but not mud to penetrate. You can't have the pipe or rock get filled with mud. There must be that space.

[Beardog]

I have never found perf pipe in Los The Thais just drill a 4" pipe every 6"-8" 2 rows about a couple of inches apart & staggered. set the pipe with the holes on the downside.covere with heavy tarp material (not the cheap porus kind) & bury the top with soil . The pipe is a bitch to drill & will tend to crack . It does not need to look pretty . If it breaks in a chunk you can just epoxy a smaller piece over it. Works great - I would buy perferated pipe but even getting soil compaction devices in LOS are almost Non Existant. A steam roller is the closest machine I found. There are a ton of downloads on TV or google on the pipe perferating methods.

[NeverSure]

Sounds good. The ditch, pipe and rock must breath oxygen since some decomposition happens there and it must be aerobic. The fabric is to let air and water pass through, but not mud. There is a special fabric for that. It is also used in road building. When the soil is compacted it is spread out on the soil. The rock is placed on that and compacted. Over the years it keeps mud from pumping up into the rock and lubricating and contaminating it. It's especially important in clay soil.

It is called a geofabric or geotextile.

Without it the ditch and pipe and drain rock will eventually fill with mud and be useless.

[canopy]

It is also perfectly suitable and common to use a layer of straw over the rock instead of a fabric.

Where might one find smooth drain rock? At building stores all I see is coarse rock for making concrete. I have seen little bags of ornamental round rock sold at landscaping places, but that would be cost prohibitive at cubic meter quantities.

[NeverSure]

It is also perfectly suitable and common to use a layer of straw over the rock instead of a fabric.

Where might one find smooth drain rock? At building stores all I see is coarse rock for making concrete. I have seen little bags of ornamental round rock sold at landscaping places, but that would be cost prohibitive at cubic meter quantities.

It isn't suitable to use straw. This is an environment of rapid decomposition and the straw will soon be gone. The rock, and therefore the pipe must be completely encased in geofabric for the lines to work properly for the long term.

I don't know about drain rock in LOS. If I couldn't get round rock which is sorted by size from normal river rock by a sorting machine, then I'd look for large crushed rock. I say large as in fist sized so that there would continue to be air space between the rocks to leave space for the waste water. If that were the case I'd certainly want very strong pipe to avoid crushing. If I'm building it for myself or for people I love, it will be sanitary for the long term.

[canopy]

It isn't suitable to use straw. This is an environment of rapid decomposition and the straw will soon be gone.

Straw has a proven history for this purpose and is code approved even today everywhere I am familiar with. Straw can degrade away in time but it gives the soil above time to consolidate and compress such that it won't be an issue clogging the rock. A quick search on the internet should confirm this. If there are disadvantages, I have yet to come across them.

[rsokolowski]

This is a good link regarding septic system requirements in the tropics. The cement rings in the ground will likely leak and this is not good if it is next to your well. A proper septic system needs a leach field.

http://esa.un.org/iys/docs/san_lib_docs/Guidelines_Aceh%20and%20Nias.pdf

Cool Thai house provides excellent advice about any building in Thailand related topic, check it out.

[NeverSure]

It isn't suitable to use straw. This is an environment of rapid decomposition and the straw will soon be gone.

Straw has a proven history for this purpose and is code approved even today everywhere I am familiar with. Straw can degrade away in time but it gives the soil above time to consolidate and compress such that it won't be an issue clogging the rock. A quick search on the internet should confirm this. If there are disadvantages, I have yet to come across them.

You are right. I apologize. I should have looked it up. It isn't used here but I see it is in most places.

Carry on.