Water Testing

stoneman · October 30, 2005

Have bought some land about 2 hours north and west of Udon Thani...

The property has a drilled well on it and I have just finished setting up a new pump and it seems to do well...The well itself is over 40 meters deep..

We have just finished planting over 250 trees ranging from avocados to mango to mangosteens and 175 rubber trees...Added to the 800 we have across the road, we are really getting into the rubber business...well when they grow up in a couple more years.

We live in Bangkok and only go up about once a month..We have a family that stays there and takes care of everything...My question concerns finding a source to test the water...We have been using it for watering the trees but not for drinking...

I need a source to send samples to or have them come and collect samples. Would like to know if there are any problems before adding the filter system for the water going to the house...

chownah · October 30, 2005

I posted this in the vegetable cleaning topic:

"I went to the provincial office for the Department of Medical Sciences. The Thai words for this office is more or less pronounced Soon Witayasat Gan Pet....so for you it would be called Soon Witayasat Gan Pet Udon Thani....I live in another province."

Don't they have one of these in Udon Thani?

stoneman · October 31, 2005

Thanks very much for the information...I will check to see if they have an office like this in Udon Thani

Appreciate

Stoneman

orchidexpert · October 31, 2005

You can ask for help from ..

Department of Agriculture Extention in Bangkok and Udon-station.

www.doae.go.th

Or at the Irragtion Dept. in BKK and Khonkhen station.

www.rid.go.th

Or. Land Development Dept. in BKK and Khonkhen station.

www.idd.go.th

They can suggest you all about how to grow that plant and farm management such as soil, climate, water irrigation,water quality+qualtity.

Free consulting.

For my eyes, water quality has no problems because runoff or overflow water came from moutain or rivers. But the peak of water in rainy season and lace in the summer time. That's bad for farming and how to manage? it is the the big point that you can got from their advisory.

Brew · November 1, 2005

try it at a univerity. at khon kaen university - faculty of technology- i've got some microbiological work done. (yeast separation and propagation, agar slants..) the price has been very fair.

Welsh John · November 2, 2005

As a matter of interest....What can I buy to put into the Well Water to sterilise/purify it???? Its in a house Im going to rent & its a bit smelly at the moment.

Brew · November 2, 2005

a charcoal filter and a UV disinfection unit. if the water contains a lot of iron a sand filter and an airator.

a big problem (like in khon kaen) would be sulphur. you have to use reverse osmosis.

chownah · November 2, 2005

As a matter of interest....What can I buy to put into the Well Water to sterilise/purify it???? Its in a house Im going to rent & its a bit smelly at the moment.

<{POST_SNAPBACK}>

Our water comes out of the ground smelling alot and our slow sand filter cleans it up 100%. The sand filter is a verticle cylinder made from concrete rings that are 1 m in diameter and 1/2 m long.....the tower is 3-1/2 or 4 m tall. Roughly the bottom third is empty and holds treated water ready for use, the middle third is sand, and the top third (actually the top half meter or so) holds untreated water which percolates through the sand to reach the bottom. It works great.

sbk · November 2, 2005

When you fill up the top bit how long does it take to percolate to the bottom?

chownah · November 2, 2005

The entire tank is always kept full and as water is withdrawn the water moves down through the sand. How fast the water goes through depends on what sand you are using and how close you are to needing to clean the sand. Very fine sand will slow the rate and courser sand will increase the rate. Our filter, when the sand was new would run for over 2 hours with our pump running at full rate withut stopping....that's about like healthy flow from a garden hose. It is totally adequate for supplying a house. As the filter gets dirtier the rate slows down until it is not adequate...you know this has happened when the pump starts pumping air. When this happens there are two ways to clean the sand....one way is to have a back flush system built in and the other is to remove the top layer of sand and either wash and replace it or just replace it with new clean sand. I have a back flush system but don't use it. When the sand needs cleaning it is only the top 10 cm approximately that gets dirty. I just put up a ladder and scoop out the top 10 cm of dirty sand into buckets and take them down to clean. It is easy to tell how much sand to remove and clean because when you dig in the dirty sand you can clearly see that you have reached clean sand by the color. I forgot to say that you empty the tank enough so the sand is not covered with water when removing sand. To clean the sand you just fill a small bucket about 1/3 full of dirty sand and then add water, agitate it a bit with your hand or a stick or something, pour out the dirty water, repeat about 6 or 10 times until the water looks mostly clean. After you have cleaned the sand this way you just put it back on top again. As I said before, you don't need to clean the old sand, you can just have a pile of extra sand and replace what you remove....but the entire process including the cleaning of the sand only takes 2 hours or less and I only have to do it about once every 6 to 9 months. There is a local guy who makes these tanks and I've seen them everywhere in the north so I think its a well known technology. I'm an engineer and before I had him build ours I researched this 'slow sand filter' technology and found that it is used in the US to purify water for towns and when I did ballpark calculations for what size filter I would need to supply one house it matched the size of the filter that they usually build so I figured it was the real deal....and it works great. We had the water tested and it came out ok to drink...so we do...and it is good tasting water......whereas before filtering it stinks noticeably.

stoneman · November 4, 2005

Chownah..

Thank you..very good information on the sand filter and I think it is a good suggestion. Just a couple of questions...The sand that is in the middle third of the tower...How is it held there? Secondly ... the bottom third where the filtered water stands, what kind of preparation did you do to that area? and finally is it necessary to seal the joint between each of the rings and if so, how do you do that...

Thanks

Stoneman

chownah · November 5, 2005

Stoneman,

The sand sits on a 'floor'. The floor is a precast steel reinfoced circular piece about 10cm thick (maybe a bit less) and with the same diameter as the outside of the rings. The floor has lots of small holes in it for the water to go through...its been a long time so I forget but it seems like they were about 2 cm in diameter or there abouts....lots of them. You stack up enough rings for the bottom storage and then you put this floor on top of the stack and then you stack more rings on top of the floor....so you end up with a tower about 3.5 meters tall (actually 3.4 meters tall because the first ring is embedded about 10 cm into the base for stability) with a 'floor located' about 2 metres up from the bottom or about 1.5 meters from the top. On this floor you first put a layer of gravel to keep the sand from falling through and then you put the sand. NOTE: You need to use white sand and not red sand. By white sand I mean quartz sand. Red sand will put minerals in your water and make it 'hard'. Quartz is really inert and won't dissolve into the water.

The rings are put in place using mortar..just like you would do with bricks or blocks. There is an additive you can buy that makes mortar impervious to water...water won't seep through. I think that they added this to the mortar. I do know that the entire inside and outside of the tower was coated with a slurry of cement and water proofing additive.....so you need to do the inside of the lower portion of the tank before you install the floor.

You end up with a tank about 3.5 meters tall which is always kept full of water. It has a divider (the 'floor') part way up from the bottom which seperates it into a portion below and a portion above which is filled with sand but leaving about 50 cm at the top for water. There is a float actuated switch that controls a pump that pumps water from the well into the top of the tank (above the sand) and keeps it full. There is another pump that connects with a pipe to the bottom portion of the tank where water is withdrawn and pumped to the house. There is a vent for the bottom portion of the tank and also some plumbing for the reverse flush system...neither of which are described here.

I did not do the work myself but I did casually watch what they did...but I didn't check out every detail since I knew that I could go ask questions later if I needed the details. I suggest that you look around and see if there is someone in your area who does this work and if there is a local company that makes the rings and the floor for this type of tank. I know that here not all rings are made the same and they vary in strengths...so....try to get the right ones.

Before using the tank we filled it, let it sit for a day, and then drained it....and then repeated about 4 or 5 times..over a period of about a week. This rinses it out and also it takes a week or two for the micro organisms to establish themselves in the sand.....this type of filter acts by biological action, not mechanical filtering, so it takes a couple of weeks for the bacteria to get established. I didn't drink any of the water for the first year....but all the neighbors came over and took bottled water home to drink. I figured I'd just keep buy bottled water (its only one baht per liter from a local provider) and let the tank get rinsed really well before I drank any.

If you want more info...just let me know.

Chownah

stoneman · November 5, 2005

Chownah

Thanks very much for the great explanation...Now I understand...My main use for the well will be irrigation of the trees, but also want to set up a system to have drinkable water while we are there. We have no plans of building there, but we will probably hire a family to live there and take care of it and I would like to supply a decent water source.. there is a house on the place that we have done some clean up and renovation to.

We are going to put in a 500-750 liter tank on a tower and pump from the well into this for storage for the irrigation and attach a pump to this to give the needed pressure for the irrigation lines.

With your information, I think it would be good to come off this tank with another line into this sand purifier and a small pump into the house...

Again thanks for your time

Stoneman