Flow-Through Rate in Liters per Minute

Thank you for these comments. Do you have any insight into my second question. It seems from the initial responses that the first option will not work due to the low pressure of the falling water. Option 2 is not very expensive, so I would like to do it, I am just not sure if it will affect the water pressure in my house, most importanbtly the pressure of water coming out of the showers.

Thanks again.

4 bar is about 58 psi. Old style unrestricted shower heads at 50 psi would run 4 gpm.

100 liters is about 26 gallons so you should be fine. US req. limit shower heads at 2.5 gpm at 80 psi. So if yours is relatively new maybe restricted to that flow. With demands on water around the world I don't see manufacture making both restricted and non restricted.

One of the main objectives of rain harvesting is to recharge the ground water. For drinking applications it is to be tested and used. For pressure the explanation given here explain it clearly.

Your shower will be fine, although filtering that volume of water all the time is going to see you cleaning/changing filters alot. You will have a gut full in no time.

How easy is it to segregate the potable water feed from the general reticulation feed in your installation?

Filtering of roof captured water is very impractical but it is possible to reduce the amount of debris that is washed into your storage by purging (and disposing) the first lot of water that washes down the catchment and then diverting the flow to the tank. This can be done manually by having the tank fill pipe so it can be moved in our out of the tank, this requires supervision, or automatically(and passively) with a float trap and diversion arrangement.

Regarding drinking rain water you should test it for contamination and minerals. If it is depleted of minerals you may deplete your body of minerals same way distilled water leaches out necessary minerals. A coral filter should add the minerals your body needs. You will find rain water excellent for washing of clothes and showering with the lack of minerals you will need much less soap or detergent. Remember birds poop on roof area and this will be in your water as well as some industrial fallout. Re my comments on distilled water should you have an overload of pollutants in your body two weeks of drinking distilled water may remove a lot of it but do not exceed two weeks. Add an ultraviolet sterilizer for safety and or H2O2 injector to take care of pathogens.

I tend to agree with you about the inadequacy of the treatment advocated. I am not sure if anyone has yet done it for a DIY gravity syphon filter but I see no reason for not being able to build one. Perhaps one of the manufacturers will be able to provide a smaller version (I am being too lazy to web search). I have seen such filters installed on surface water applications for small systems and they work extremely well. These filters should easily get down to fifty micron filtration but you will need much greater reduction. The Canada-7 state criteria for filtering surface water is to provide at least 1 micron (NSF approved only) or chemically assisted filtration. With some form of disinfection (40,000 mJoule flux UV (this is a minimum acceptance but larger is better), or chlorination) you could use that water for showers or bathing. My preference would be to chlorinate as the water may sit for long durations before needing a backwash.

For potable water the user will need or should use reverse osmosis as the only safe method for use. And always remember that the birds don't just sit on the roof.

I do not know of any water company which cannot reach potable standards by means other than RO. RO is normally used to desalinate water. I would not expect rainwater from a roof to collect enough salt to cause issues.

From being in the business for many decades, I suspect there are many companies that would not treat roof water to potable standards without the use of RO. I also would agree that many waters can be treated successfully without RO. The problem is that the water treatment can be very complex when dealing with roof water. It is low in dissolved solids but can be very high in organic, viral and bacterial components. Oocysts can be difficult to treat. There are even fungi and molds to contend with from roof water. Many Pseudomonas type bacteria are less than 1 micron as are many viruses. Roof water will also vary with time and with contamination introduced. Chemically assisted filtration where flocculation, sedimentation, and filtration are applied is a standard practice for most surface water treatment. However, for a small private use 1 micron absolute filtration, UV and RO may prove to be the simplest method with the fewest maintenance issues. RO has more applications than to remove salts. The RO would also remove the potential for harmful organic compounds that can leach from a roof.

One other problem is that the use of rain water can impart a very low pH which can make the leaching of metals from the plumbing an issue. If I was designing such a system, I would make allowances to correct the pH.

Filter enough for washing & cleaning after the capturing tank. Further filter and sterilise only what you will ingest to a third tank for drinking water. This way, the maximum quantity can be captured, larger debris will be held in the first tank (make sure outlet higher than silt will be allowed to accumulate). First set of filters can be run below maximum rate, which will allow them to capture more before they need replaced/cleaned. From second tank, a small sterilisation system can be used to provide drinking water, either on demand or to a small (10l/2gal?) tank. No sense treating more than required!

If you want to filter the incoming water you will probably need about four stages, each easily cleanable. The stages would be: Coarse, Medium, Fine, Silt.

Coarse to catch leaves, twigs, etc

Medium - small seeds, etc

Fine - dead insects, pollen, etc

Silt - dust

A Silt filter requires a massive reduction in flow rate and settling time.

Each section will require an overflow to accommodate blockage, and the first three will require cleaning after each fall of rain.

I have the first three, but have not yet determined how to implement a silt filter in my installation.

WAWAUS:

I don't have a water recharger, nor am I collecting rainwater, but I did install a storm drain system and I get a handful of silt every 3 to 6 months or so. I should have saved some of the mud and got it analyzed.

The storm drain collection (4" pipe) now is from gutters and a very shallow swale with no vegetation, but a bush covering the area. The eventual plan is to place an underdrain made from EZ-flow (from here http://www.ndspro.com/ ) under it.

I wanted to try to get one of these: http://www.remfilters.com/uploads/products/REM-Triton-Drop-Inlet-5-07.pdf but manufacturer Triton wasn't very helpful. They are expensive. The distributor (REM) can't sell it to me. REM has been helpful but I haven't pursued all of the leads aggressively.

I can't even get Triton to tell me what trench drain (another application) models does their trench drain filters work with. It might be a quantity thing, who knows.

One of the nice things about Triton's design is that overflow protection is built-in.

I'm using this D-box: http://www.polylok.com/catalog/product/12%22%20Round%20Drain%20Box and for the most part, the inserts appear to be custom. My D-box is quite small and therefore a problem. If I could get a hold of the media and cage, I could probably make something work. Note that it latches on the bottom side "somehow".

In any event, i had to take matters into my own hands. With silt, your supposed to aim for 40 um filtration. http://en.wikipedia.org/wiki/Soil_texture

The eventual plan is capture water from the back yard (hill) into a shallow swale and discharge into a D-box. From the side (3 feet away) there will be roof runnoff from a gutter d-box. This will continue using EZ-flow as an underdrain for 30 feet from http://www.ndspro.com/ . It will then empty into an existing catch-basin that is also fed from about 3 feet from the side from a gutter.

Then stormwater travels 20' using SDR pipe and then through 10 feet of EZ-flow for drainback purposes, then 3' of solid schedule 40 under the sidewalk, then there is about 2.5' of schedule 40 with holes sitting on top of drainage rock and then to a pop-up about 14" from the street. Under this 2.5' section is a water main.

The gutter water is pre-filtered using this: http://www.egutter.com/GUTTER-GUARDS-AND-LEAF-GUARDS/The-Wedge It catches all leaves and some seeds. The gutter enters the side of the catch-basin, so I don't have to worry about snow.

So, what I decided to do was to get a filter like this one http://www1.mscdirect.com/CGI/NNSRIT2?PMPXNO=4602025&PMTERM=ko50k4s, the ko50k4S from USFILTER and install it into the outlet of by D-box. The filter has a 1/4" round lip and fits the SDR pipe perfectly and it's 14"long. The pipe that extends inside is a bit short, but I was able to make it work by adding a 1/2" ring of SDR pipe.

The catch basins has totally eliminated water in the basement and for now, the back roof gutter empties into the catch basin through a piece of corrugated pipe sitting on the ground.

It's only been installed a few days and there was a pretty good rain event and it's looking good. I'm expecting that semi-annual inspections and inspections after large rain events will be necessary. I'm pretty confident that the system will work out and I have two other places where it will be necessary too. This location can survive without a bypass and it's easy to create one when installing.

The other drainage problem will have to discharge into a dry wells and there I really need a silt filter.

Here is a link to some critical pictures as the system was constructed: https://skydrive.live.com/redir?resid=F3617EE527915CBB!139&authkey=!ANhncGrPMZg8F8Y It really needs a pic of the filter media.

The soggy lawn pic is yet another problem that needs solving. The grass gets drowned. It's a shady and wet area

So, I think I'll be in good shape with regular maintenance and I'm not sure if I want to do some sort of cascade arrangement for the dry wells such as filter at 200 um and maybe 10 um. With a bypass, I should be set.

This system basically addresses houses in a development which has house, driveway, 10' of grass, house, driveway, 10' of grass house, etc. The short side of the house is on a hill. New landscaping by the neighbor has necessitated all of this work. A window well will fill with water when there is a hurricane, but a 12 V bilge pump sits in the well. I must remember to turn on the power supply for a big event. For the most part, I would rather not relay on power, but the area is pretty good with little power issues.

I don't really have to worry about hydrocarbons and slowing the velocity is important.

The 100 yr event design called for a system that could handle 40 GPM and the filter is rated for that as well.

I hope the sock filter gives you some ideas. It cheap, the first filter cost me about $50 and subsequent ones will only cost about $9 USD with a media cost of $4-5. Filter replacement requires no tools. The clamps were made using a Dremel (sanding disk), jigsaw and a drill (1/8" bit and a countersink bit).

Any comments appreciated. Thanks.

The soggy lawn pic is yet another problem that needs solving. The grass gets drowned.
You don't state whether the lawn itself has a fall toward the access road or not. Investigate draining the lawn by trenching. Fill with layers of aggregate (from the top: coarse med & fine), with the drain direction leading the water off your property.
You may need to cover the aggregate first with a permeable mesh or shadecloth, (depends on your soil type), or you may find the soil eroding from the underside of the lawn via the trench.

That was a pretty comprehensive description of your storm water drainage system. Thanks for sharing.

I don't follow why you need to filter all of this water? Where does it eventually go?

I did like the self clearing gutter spout sieve. I see the sense in that to prevent blockages due to leaves but the rest seems a bit excessive (without knowing the full picture there)

Before your neighbour did their landscaping did you have a problem? What did their landscaping actually do to your property? Sounds sus to me....

Have you looked at something like a geotextile for your soggy grass?

I recently found this: http://www.smartdrain.com/ that looks like a solution for the soggy lawn.

The lawn slopes from as high as 7% to 3% from the back yard to the front yard (street) in a 10' x ~100 foot long space. That space contains a hill about 2' high through some of that space located in the back yard.

After the hill, the back lawn has a noticeable slight slope the way the soggy grass is taken. I havn't measured the slope. The idea is to "capture" the water at the top of the hill into a trench (vegetation/grass swale), collect it in a D-box and have it go out at the street. Right now, the back yard trench is designed to make the lawn soggier while keeping the water away from the house. The swale and underdrain will also collect some surface water between the driveway and the house (the 10' x 30' strip). 30' is the house dimension. Agreed, the soil composition has to change there to a sandy loam mix on top of the EZ-drain. I'll have ~6" to deal with. 3" has to be viable soil.

The "silt filter" is necessary because there will be 40 feet of EZ-drain in the system once complete. There is 10 feet now. I don't want that to clog. The "handful" of mud in the pic by the pop-up is what I removed from about 3 months of spring rains. It's not nice to put silt into the county's storm drain system. The white piece of gutter that is sitting on the ground is the ground portion of the water with silt during an event.

I'll also need a silt filter for another system which will use 3 x 40 gal dry wells.

The neighbor's landscaping (prior):

Was a chain link fence + hedge (our side) and a raised flower bed that allowed the water to exit about 3' from their house on the driveway. Diagonally, it's about 20' from the point of entry into our house. The water had plenty of time to get absorbed into the flower bed. We were also dumping about 3/4 of the roof water along side of the house.

The neighbor's landscaping (after)

A 6' wooden fence was constructed. A tent (aprox 25' x 15'), an ersatz garage, was placed in his driveway. Now lots of flooding in the basement. The tent had to be moved due to code violations. The raised flower bed is gone. The edge of the tent is about 6' from the trench. The driveway was given a raised edge by the landowner. But water knocks it down. He also diverted more of his roof water into his driveway. A chain-linked fence gate was placed in front of the tent. The chain link fence and hedge is still there. We moved our gutter discharge to the front of the house along the ground.

Current: A shallow, no vegitation swale, hits a small amount of silt fence and then enters the storm grate and mixed with 1/2 of the roof water from above the grate and 1/4 of the roof water below the grate. The 50 um Filter, filters this water, passes it 20' through SDR pipe. Simplisticly, there is 10' of EZ-Drain for drain back and a pop-up. (Not quite, but close enough)

A swale was created in the back yard, but it's sloped toward the center of the length and dumps into the middle of the yard away from the house.

Future:

The above will drain toward the street and dump into a D-box which will have 1/4 of the roof water mixed there. That water will be filtered and passed through 30' of EZ-Drain where it will enter the d-box already installed. The surface run corrogated pipe will be removed.

The county said "He can pave his entire back yard and we could not do anything about it. If he stuck a pipe from his yard to yours, we could."

Alternatively, if you used an Agi (Agricultural drain - corrugated perforated plastic) drain enclosed in a geotextile sock buried under gravel along the bottom of your swale all the way to the street, the water will filter through the gravel, through the geotextile, leaving the silt behind and then flow through the clear Agi drain to the street. No pits! you could also 'T' your downpipes directly into the Agi drain

I added to more pictures in an - Anticipated folder: https://skydrive.live.com/redir?resid=F3617EE527915CBB!153&authkey=!ANhncGrPMZg8F8Y

489 is where the beginning of the swale starts and 491 is a pic taken from the opposite way of water flow, but along the same path.

You can see the path, the edging and the tent.

489 is a swale with no underdrain, then the planned d-box. 491 is, from v=back to front, the planned d-box, the 30' EZ-flow route and the existing D-box.

Where did you say you are located?

I live in the East mid-atlantic region of the US.

The EZ-Flow.EZ-Drain is corrogated pipe, wrapped in polystyrene peanuts and a geotextile fabric without the rock. The only issue with this stuff is that it has to be burried deeper. It's 10" in diameter and it needs a min of 6" cover so it is basically the same as the AGI-Drain.

My swale (near the house) really doesn't have any resonance time and it's located midway between a driveway and the basement foundation wall which is about 10 feet. I really can't have any resonance time there because water would find it's way into the basement. The velocity is high enough that silt is being collected. Furthermore, nearly the entire area is covered by a HUGE fig bush making grass growing difficult. The pics showed a winter/fall picture. It looks way different now.

This is where the AGI drain/EZ-DRAIN will be burried. It has to have some sort of swale-like shape, so that water running from the driveway will "catch" there and any water will collect in the center of the swale.

Soil has to be such that it will drain easily onto the EZ-Drain. Suggestions indicate that a 50/50 mix of sand/loam, sand then with a geotextile fabric if doing it the conventional way. Some other suggestions is to replace the geotextile fabric with 6" of pea gravel, but I don't have the room for that. I don't know if it is a good idea to place impermeable fabric at the bottom of the trench.

What would be a good idea is to create a 6" wide x (18-24" deep) x 30 feet long wall of pea gravel which would slow down the velocity of the water. I could, for that matter, make the the entire top of the EZ-Drain be sand and have pea gravel at the top. What I don't like about the pea gravel exposed surface is possible neighbor flack and picking up small stones with the lawn mower. Possibly a layer of larger stones such as Lava Rock on top would work. The purpose being to reduce the surface velocity. I'm going to have a hard time getting grass to grow.

In the other area where no underdrain is planned, but could be added is essentially the flower bed of a hedge. Probably at least 10 linear feet near that area will have burried sandbags for a wall. It could have a piece of EZ-drain installed there since I may have one left over.

some other Items and docs you may find interesting/ useful:

http://www.dlist-asclme.org/sites/default/files/doclib/upload%20December.pdf

http://www.starkenvironmental.com/a-1-filtration.html

http://www.rainwell.com.au/rfd