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Conference 7.286::home_work

Title:Home_work
Notice:Check Directory (6.3) before writing a new note
Moderator:CSLALL::NASEAM::READIO
Created:Tue Nov 05 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2100
Total number of notes:78741

192.0. "Dry Wells" by BARNUM::JORGENSEN () Thu Jul 16 1987 12:23

    
    	I am going to be putting in a dry well for the downspout of
    	my gutters. Can anyone make any recommendations about getting
    	crushed stone/gravel in the Worcester/Leominster/littleton
    	areas? Any comments on the size or construction of the drywell
    	will also be much appreciated! Thanks in advance.
    
    /Kevin
T.RTitleUserPersonal
Name
DateLines
192.1here's one way.DRUID::MEANEYJIMThu Jul 16 1987 17:3456
    Kevin,
       
    No suggestions on source for drainage material, but a couple of
    thoughts on construction.
    
    When building it, keep in mind that eventually you may need to clean
    it out, so make sure you can un-construct it enough to scoop out
    the buildup of decomposed organic material that will eventually
    clog it up.
    
    Depending on how much room you have to work with, the size of the
    well can vary, but in general, the bigger it is the less often you'll
    have to clean it out.
    
    You can get fancy and carve a cylander shaped hole in the ground
    and line it from top to bottom with red brick and a manhole-type
    cover over it for easy cleanout.  Two of the seven drywells around
    my house are this type.
    
    The others are out from the house about four feet or more.  I've
    cleaned a few out recently and they vary in construction.  One was
    just a clay pipe from the downspout running on a slight downward
    angle to a hole filled with rocks of different sizes. There was
    no cover over the end of the pipe and rocks though, so the earth
    that covered the hole contributed to the clogging sooner than if
    there was a cover.
    
    One that I rebuilt, based on a chapter in a book I have, looks like
    this;
    
    | |
    | |
    | |<-downspout
    | |
    | |				|- Ground level
    | |				V
    --------------------------------------------------- 
    \ \				        ________
     \ \_______________________________|__      |
      \________________________________|__ 	|
      ^				       |*%*%*%*%|
      |				       |%*%*%*%*| < barrel or other
      - Clay Pipe (drawn level,but     |*%*%*%**|   suitable container
    	should extend at a downward    |_ __ _ _|   with drainage holes
    	angle. (About 1"per foot)		    in bottom, drainage
    						    material in lower
    						    2/3's and 'removable'
    						    cover over top.
    						    
    If you don't want a removable manhole-style cover visible at ground
    level, set the top of the container under the ground surface enough
    to have adequate topsoil for growing grasss etc., at least 4-5".

    Good luck, and I hope you get a few more ideas from other folks.
    
    Jim
192.2Advice to installation/question3D::WHITERandy White, 3D::White, DTN 296-6674, EXT (617)480-6674Thu Jul 16 1987 17:5425
       
	I too need to hookup two downspouts to a dry well.  Having just
	connected to town sewer I have my old cesspool/leaching field
	that has been pumped and filled with gravel to tie into.  My
	question is this:

	About 4 months ago I saw an ad in one of the homeowner's mags
	from a company that made corrugated plastic drainage pipe.
	This stuff was nice in that it was flexible, i.e. easy to work
	with, and had end caps that attached to the base of the downspout
	sealing out leaves and dirt, assuming of course leaf screens in
	the gutters.  Does anyone have any experience with this or
	remember the name of the company?  I meant to send off for info
	but can't find the ad.

	Thanks

re:-1	I would definitely recommend some kind of sealing around the base
	of the downspout as well as any joints.  My house had an old system
	where the sewer line was run and the inlets by one of the downspouts
	was packed solid for about two feet from material around the opening
	and dirt from around the elbow where it joined the main pipe.

	Good Luck
192.33D::BOOTHStephen BoothThu Jul 16 1987 18:549
    
    
    	Proctor in Lunenburg will deliver crushed stone and is very
    resonable. 
    	Just put a piece of screen over the drain spout before entering
    the dry well and you should not have to clean it out.
    
    	-Steve-
    
192.4FDCV13::SANDSTROMFri Jul 17 1987 17:308
    
    	You can also try:
    
    		San-Vel in Littleton	486-3501
    		Keating in Lunenburg	582-9931
    
    	Conni
    
192.5WELFAR::PGRANSEWICZFri Jul 17 1987 20:3810
    RE: .2
    
    The corrogated plastic drain pipe you refer to can be bought at
    Sommerville Lumber.  I think I'm going to use it for my drains too.
    They always have it on sale for $25 for 100'.  I looked at it in
    the store and it certainly felt pretty heavy duty!  They also had
    some Y connectors for the stuff.
    
    Phil
    
192.6Q::ROSENBAUMRich Rosenbaum;mail-&gt;Boehm::RosenbaumMon Jul 27 1987 21:102
    Please note where you eventually get your crushed stone, location,
    price, etc.  Thanks.
192.35Set tubs and dry wellsAMUSE::QUIMBYMon Feb 22 1988 14:0628
    There is a soapstone set-tub in the basement of our new (50 year
    old) house.  The inspector pointed out the grossly corroded trap,
    said it should be replaced.  So I did.  There is now a nice, neat
    PVC trap.
    
    But the set-tub still will not drain.
    
    Although the house has town sewer, the set-tub drains into a smaller
    pipe, which goes down to a hole in the basement floor and angles
    out from there -- looks like it's going to a dry well.
    
    A plumber who was in for another reason said that the dry well was
    probably saturated, that reaming the drain pipe probably would not
    help.  He said the only solution is probably a pump (the sink drain
    is lower than the house's main DWV pipe).
    
    There are dry wells around the house, as well, for the gutters to
    drain into.  They seem not to work either.
    
    Is there any way to rehabilitate a dry well, short of digging it
    up and rebuilding it ??????
    
    Any experience with set tubs that drain this way (suggestions
    gratefully accepted).
    
    Thanks,
    
    dq
192.36Sorry for the bad news...VLNVAX::SUMNERSenility has set inTue Feb 23 1988 00:389
    	 Dry wells are supposed to be dry when they are not receiving
    	water. If your drains are not working this time of year then
    	my freindly advice would be to (a) make sure you have access to
    	pump this spring and (b) start making plans to dig up your yard
    	this summer because I don't beleive that there is any way to
    	bring dry wells back from the dead.
    
    
    	Glenn
192.37Dead Dry Well?CASV05::DEADERICKJoan E. DeaderickWed Jun 08 1988 14:119
re .1  Is there really no way to bring dry wells back from the dead?

Why do they fill up anyway--does the water table rise?  I have a washing
machine which drains into a dry well and which has worked fine for years
(except during wet Springs), but now two loads of laundry cause water to
run steadily back into the basement from the standpipe. (I have a pail to 
catch it).

Joan Deaderick
192.38MTWAIN::WELLCOMESteve Wellcome (Maynard)Wed Jun 08 1988 16:263
    My guess is that over the years lint, detergent buildup, soap scum,
    etc. clog up the ground in the drywell so it doesn't drain anymore,
    or at least not fast enough. 
192.39one experienceCSSE32::NICHOLSHERBWed Jun 08 1988 16:4622
    It MIGHT be high water table. On the other hand...
    
    We had a dry well intended to receive sink/washing machine runoff.
    It started backing up occasionally about 15 years ago, sometime after
    we moved into the house. After several applications of "acid", and a 
    rotar rooter call we were advised that the dry well "wall" -cinder blocks-
    was lined with grease to such an extent that the well had become
    virtually completely non porous and therefore non-usable.  (i have 
    the impression that older rural and semi rural dwellers recognized
    this as a permanent part of the "cost of doing business" in areas
    without sewage systems -i.e. every "n" years build another dry well-
    (or for that matter dig another outhouse). Not sure what the life
    expectancy of a dry well is.
    
    In our case the failure would have been about 15-18 years after the
    house had been built and the dry well installed. At about the same time
    our septic system went. When we had the septic system installed, the
    indoor pipe to the dry well was rerouted to the new septic system. 
    
				gee aren't i cheery
    				herb
192.40JOET::JOETFri Jun 10 1988 12:5710
    I have a dry well that is exclusively attached to our washer.  It
    started slowing down a while back (EXACT same symptoms as .2, except
    not varying with the water table). I assumed that it was lint and such,
    so I dumped an excessive amount of drain cleaner down the pipe and it
    cleared it up significantly. 
    
    -joet
    
    P.S.  Maybe there's a market for washer second load overflow buckets in
    designer colors. 
192.41RGB::SEILERLarry SeilerSun Jun 12 1988 21:456
Hmm... the stuff that goes into a dry well goes directly into the
ground water, yes?  Surely it's not a good idea to dump lots of drain 
cleaner into the ground water?  What about detergent?  

	Thanks,
	Larry
192.42Can you say lint trap?AKOV88::CRAMERMon Jun 13 1988 17:5216
    In the search for our septic tank we stumbled across the old dry
    well for the washing machine. Now, we had only been in the house
    for a year and the washer emptied into the septic system, but, we
    had been told that this was done because the dry well backed up.
    On digging up the dry well it was very easy to see why the thing
    had backed up (It was the old fashioned rock filled kind). Every
    nook and cranny visible was full of lint that had been so compressed
    it resembled fuzzy concrete. Not hard to see why water may not
    percolate easily.
    
    re: .6
    
    Which is probably the reason that dry wells are illegal in alot
    of places (including Northboro, where I live) now.
    
    Alan
192.43What do you do with an old dry well?BUFFER::JONESWed Jul 26 1989 18:548
    I need some help.  What do you do with a dry well when you don't use it 
    for the washing machine?  We just had some trees cut and the weight of
    a tree falling on the ground broke the lid of the dry well which we did
    not know existed.  Now we don't know what to do about it.  Any
    suggestions are appreciated.
    
    Sande
    
192.44questions ... suggestionsMRFLEX::RECKARDJon Reckard, 381-0878, ZKO3-2/T63Thu Jul 27 1989 11:1310
Do you want to keep the well and fix the lid?  If so, what was the lid
made of - wood, concrete, other?  How big?  If it's close to the house,
the well might serve as a root-cellar or cold storage place.

Do you want to remove the well?  Again, what's it made of?  Sounds a bit too
masochistic for this DIY-er.

Do you want to fill in the well?  I'd think I'd fill it with something that
will drain water well - maybe just coarse sand (that's the cheapest "fill"
our excavator used to cover our septic system) - then loam on top for grass.
192.45We filled it in57462::JONESMon Jul 31 1989 16:1812
    Since the Tree Service men and equipment were still at the house, we
    had them crush the dry well inwards and fill.  Now it just has to be
    seeded.  It seems to me there should be a law that mandates sellers of
    property should make the buyer aware of all "holes" in the ground such
    as wells, dry wells and septic tanks.  We have found the well and the
    dry well.  I just hope no one falls in the septic tank before we find
    it.
    
    Thanks for your help.
    
    Sande
    
192.7What's a dry well?SSAG::SUSSWEINSki for real, with a free heelWed May 01 1991 18:3817
    I'm considering buying a house that has a dry well septic system. 
    Problem is, I've never heard of a dry well before and don't know what
    it is, and whether it is a good, bad, or indifferent type of septic
    system.
    
    Can anyone in here give me a quick description of what a dry well is,
    and whether it's something it's something I want for a septic system?
    
    Some background:  The house is located on a steep hillside in the town
    of Green Mountain Falls, Colorado (10 miles from Colorado Springs).
    Most of the houses in the area have their own septic systems (no town
    sewer).
    
    Thanks,
    
    Steve
    
192.8what's in a wellCECV01::BEANAttila the Hun was a LIBERAL!Thu May 02 1991 02:188
    a dry well is a well dug (sometimes) and often filled with gravel or
    some such that has no water in it.  it is used to put water INTO as
    opposed to take water FROM.  I have one at my home in Vermont into
    which I drain "grey" water... that is, water which has no solid waste
    or food in.
    
    tony
    
192.9TOKLAS::feldmanLarix decidua, var. decifyThu May 02 1991 14:1720
"dry well septic system" is an oxymoron. 

This house could have a leach pit, instead of a leach field.  A leach pit is
used in places where you don't have enough surface area to build a leach
field, but you're high enough above the high water table to dig down.  
It's a similar concept to a dry well, except that you still have a septic
tank between the house and the leach pit, and a leach pit requires a bit
more engineering and care in construction, to insure that the leachate seeps
into the ground at a reasonable rate without clogging the pit.  Leach pits are
not a DIY project, at least not in a state as densely populated as NH or most
of southern NH.

Or it could have a dual system, with the black water (toilets) going to
a regular septic system, while the grey water (laundry, and sometimes sinks
and showers) going to a dry well.  While this is frowned upon in some areas,
I believe it makes for a much better arrangement.  By excluding the grey
water from the septic tank, the septic tank has a better chance of doing its
job, which is the decomposition of biological waste.  

   Gary
192.10It's a leaching system.SALEM::LAYTONThu May 02 1991 14:2911
    I had a septic system that had a septic tank that then emptied into a
    dry well ( it was like a septic tank with a few dozen holes in it). It
    was set into a larger hole that was lined with 1/4 or 1/2 inch stone. 
    The entire system ( and house, I might add) was on a sand bank with
    excellent drainage.  
    
    Basically the drywell is used in place of the leach field.  If you have
    coarse sand, and a low water table, they take up less room, and are
    somewhat cheaper to install.
    
    Carl
192.11RANGER::PESENTIOnly messages can be draggedFri May 03 1991 10:3511
Some friends in Mass. have an old septic system that is dry well ONLY.  It was
built from cinder blocks, surrounded by sand and gravel.  When they installed 
a pump for the toilet and washer installed in the basement, the pressure caused
the far wall of the well to collapse.  It wasn't a pretty sight.  They had the 
unit replaced with a pre cast dry well.  A septic tank and leach field would
have required them to reroute the septic pipe around their house from the back
to the front yard, remove all the trees in the front yard, and so on.  It 
would have ended up costing them about half as much as they paid for the house.

By the way, this system has been working for the house for about 40 years with
no problems, except for the one they caused with new plumbing.
192.12I had one tooFLOWER::HILDEBRANTI'm the NRAFri May 03 1991 13:326
    Re: 1332.11
    
    Thats called a "cesspool". They were popular in the past. Basicly they
    are a sepitic tank and leaching field in one unit.
    
    Marc H.
192.13Need help on how to DIY a drain/dry well...SASE::SZABOIn fact, it's a gas!Fri May 03 1991 13:3619
    In trying to solve the drainage problem of my neighbor's driveway
    which, during heavy or continuous rainfall, overflows into my backyard
    causing it to flood out, I've been thinking about the possibility of a
    dry well, especially now that we want to add a considerable amount of
    loam which would create an even bigger problem for my neighbor...
    
    Anyway, a contractor suggested simply digging a hole 15' deep and about
    4' x 4', lined with cinder blocks and topped off with a metal grate,
    for a total of $1K.  Since this estimate makes me consider doing this
    myself with the help of my neighbor (it's his driveway!), I'd like some
    other thoughts on how to do this economically and without too much
    back-breaking work.  First of all, the contractor admitted that this
    huge hole he'd dig is overkill, but pointed out that even in extreme
    conditions, no way would that thing ever get full enough to overflow. 
    I agree but, any opinions on what the minimun dimensions I could go
    with?
    
    Thanks, 
    John
192.14guestimatesKEYBDS::HASTINGSFri May 03 1991 14:0339
    well I'm no civil engineer but...
    
    	IF you neighbors driveway was 10 ft by 20 ft. and we assume that
    all of the rain that falls on his driveway will end up in your drywell
    we can calculate that you are trying to drain 200 square feet of rain.
    
    	IF we get a *foot* of rain on the same driveway you will need to
    drain 200 cubic feet of water.
    
    	A dry well of the dimensions 4x4x15 has an empty volume of 240
    cubic feet. Considering how often we get a foot of rain in these parts
    I guess that you could squeak by with those dimensions ;-).
    
    	The point is you need to estimate the square footage of ground that
    needs to be drained, an multiply that by the volume of rain that you
    might expect worst case and how quickly you might expect to see that
    volume. Next you need to calculate how fast (ie: the gallons per minute) 
    that the dry well will empty.
    
    	In my calculations I choose the volume of 1 foot of rain over 200
    sq ft. If that occurred in 1 hours time your drywell would just fill up
    and could take its time draining. If you got 1 foot of rain every hour
    for five hours you'e need to have a dry well that would drain at a rate
    of 200 cubic feet per hour. (Of course by then youd probably be more
    interested in your boat than a dry well.
    
    	Anyway I hope this has given you some idea of how to calculate your
    needs. The tricky part is really estimating how much area will drain
    into your drywell, and how fast the soil around the drywell can let the
    drywell drain.
    
    	Since you are looking at DIY, consider just digging a hole and
    filling it with rocks. If this dry well is not sufficient you can
    always dig another. Depending on you soil this may only involve a few
    hours labor. A hole 3x3x3 should offer some relief. Make a before and
    after estimate and you may be able to guestimate how much more dry well
    volume you need to add.
    
    	good luck
192.15SASE::SZABOIn fact, it's a gas!Fri May 03 1991 15:3519
    re: .14
    
    Excellent reply, thanks!
    
    >Since you are looking at DIY, consider just digging a hole and
 >   filling it with rocks. If this dry well is not sufficient you can
 >   always dig another. Depending on you soil this may only involve a few
 >   hours labor. A hole 3x3x3 should offer some relief. Make a before and
 >   after estimate and you may be able to guestimate how much more dry well
 >   volume you need to add.
    
    Another neighbor suggested something similar, only he said to go down 
    about 5'.  Can I fill over this hole filled with rocks with loam, and 
    grass over it, or do the rocks have to be exposed?  Also, our subsoil
    is clay, which attributes to the poor drainage we are all experiencing
    in our neighborhood...
    
    Thanks again,
    John
192.16How's this?KEYBDS::HASTINGSFri May 03 1991 19:4592
    For best results you really need to get below the clay layer,          
    otherwise you will just be digging a clay pot of sorts. Breaking
    through this layer should allow fo much better drainage.
    
    	As far as covering the thing over that is a problem. You need a way
    to get the runoff into the well. If you don't want to line it and put a
    grate over it I would recommend getting some gravel and pipe to direct
    your runoff into the well. THis would be more work but the results
    should be worth it.
    
    	Start by digging a trench perpendicular to the slope of the
    property. The bottom of the trench should be sloped in such a way the
    water will flow down towards the well. Lay a perforated pipe in this
    trench and run it to the dry well. Fill in the area above the pipe with
    gravel. Any runoff will hit the gravel and drop into the trench. There
    is will be carried off by the preforated pipe to the well. This will
    mean that you will be able to dig the well a little deeper and top it
    off with loam etc... You may want to fill the well with larger rocks
    then add on smaller stones in layers so that your loam won't simply be
    washed into the well with the next rain.
    
    	If you get really elaborate you might layer your materials like
    this:
    
    
    
    	|||||||||||||||||||| - grass 
    	********************
    	******************** - loam 
    	******************** 
    	::::::::::::::::::::
    	:::::::::::::::::::: - sand 
    	::::::::::::::::::::
        @@@@@@@@@@@@@@@@@@@@ 
        @@@@@@@@@@@@@@@@@@@@ - 1/2 inch stone
        @@@@@@@@@@@@@@@@@@@@ 
        88888888888888888888
        88888888888888888888 - 1 inch stone
        88888888888888888888
        OOOOOOOOOOOOOOOOOOOO
        OOOOOOOOOOOOOOOOOOOO - 3 inch stone
        OOOOOOOOOOOOOOOOOOOO
    	BIG ROCKS BIG ROCKS
    	BIG ROCKS BIG ROCKS
    	BIG ROCKS BIG ROCKS
    	BIG ROCKS BIG ROCKS
    	BIG ROCKS BIG ROCKS
    	BIG ROCKS BIG ROCKS
    
    
    
    The top view of the trench and pipe might look like this:
    
    
    
          AREA TO BE DRAINED
    ------------------------------------
    |	   |                            |
    |      |                            |           
    |      |                            |           
    |      | slope (run off direction)  |           
    |	   |                            |
    |	   V                            |           
    |                                   |
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - gravel and pipe filled trench
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
                 | |
    		 | | pipe to dry well 
    		 | |
              XXXXXXXX
              XXXXXXXX - dry well
              XXXXXXXX
              XXXXXXXX
    
    
    
    
    Or looking from the side in cross section:
                                                               ||||||||||||
                                                    |||||||||||
                                              ||||||
                                       |||||||  <--- direction of run off
                                   ||||
|||||||||||||||||||||||||||||||###|
        ::::::::::::   pipe   |###|
        |          ===========|=O#|
        |  dry     |           ---
        |   well   |                 
        |          |
        |          |
192.17TOKLAS::feldmanLarix decidua, var. decifyFri May 03 1991 21:0811
Great.  Let's just pipe all the fertilizer, pesticides, and herbicides
directly into the water supply, bypassing whatever natural filtering
can take place in the upper soil layers.

Please forgive my sarcasm, and please check with your local
authorities.  It's entirely possible that what you're proposing is
quite safe, and my fears are unwarrented.  Or perhaps you live in an
area where your drinking water doesn't come from ground water.  Then
again, who knows?

   Gary
192.18use insulation coverCROW::MATTHEShalf a bubble off plumbFri May 03 1991 22:577
    
    You might also consider putting a layer of fiberglass -unfaced- over
    the rock prior to backfilling with sand and or dirt.
    
    This allows water to drain through to the dispersing rock but not allow
    the sand and dirt to refill the hole between the rock thus degrading
    the performance of the dry well.
192.19problem/solution?KEYBDS::HASTINGSMon May 06 1991 13:1622
    re: .17 Gary,
    
    	Perhaps if you stop to think about it for a moment you will realize
    that constructing a drywell is not going to make any significant
    difference to the problem of "fertilizer, pesticides, and herbicides."
    
    	The dry well does not cause the problem, use of those materials,
    especially if done improperly does. Let's try to keep straight what the
    problems source is, that way we can best address how to fix it.
    
    	If the drywell is not constructed, the runoff could very well be a
    much worse problem. With a fast runoff the hazardous materials might be
    carried off to a storm drain and into the sewer system where is will be
    an even bigger problem. Adding a dry well might be just the thing to
    get these materials into the layers of soil that will do the filtering
    that you are so anxious to see. Clay soil is not very good at filtering
    anything.
    
    	You do have one good point though. I would be concerned about
    putting in this drywell anywhere near a well site. It might bring in
    contaminants from your neighbors lawn *and* driveway. (Let's not forget
    the occasional motor oil and gasoline spills.)
192.20Clay comments.XK120::SHURSKY&lt;DETOUR&gt; Easy Street under repair.Mon May 06 1991 14:2620
Re: .19

Actually clay is very good at filtering.  Its very small particle size and high
surface area account for this.  Clay filters out all particulate matter larger
than the interstices between grains (which is quite small).  Chemicals that are
dissolved in the water are a different matter.  To remove chamicals a large
surface area helps but you need some chemical attraction to bind them to the
surface.  Activated charcoal is good at this for example.

Clay is very good at retaining water.  Clay is what they use as the core of
earth dams (my CE degree is showing again).  If you dig a hole in clay and 
wait for the water to go away, it may be a long wait.  A dry well in clay will 
only solve the problem to the extent of the volume of the well minus the sand
and other filler contained therein (unless you run into the water table, then 
it will be less).  Any more water will run off as before.

Your best option is to guide the water to some spot where it does not cause a
problem.

Stan
192.21KAHALA::FULTZED FULTZMon May 06 1991 15:3110
re .17

What would you propose to alleviate water drainage problems?  The problems of
fertilizer and chemical contamination will occur regardless of whether a drainage
plan is in place or not.

This is not altogether different from what is used when a road is put in place,
I bet.

Ed..
192.22KEYBDS::HASTINGSMon May 06 1991 20:0110
    re: .20
    
    Thanks for the correction. :-)  What I meant in my reply was what you
    described in that in a typical dry well, waiting for the water to
    filter through the clay is not a viable option. Too bad that.
    
    	I propose that as long as solving one problem (drainage), does not
    make another problem any worse (toxic materials), that it is all right
    to solve the first problem.
    
192.23TOKLAS::feldmanLarix decidua, var. decifyMon May 06 1991 20:4329
I guess that the one point I was trying to make (in an unacceptable Friday
afternoon style) is that the upper layers of the soil play an important role
in breaking down some chemicals, especially fertilizers.  It has to do with
the presence of aerobic bacteria and other organisms.  Once you go below that
layer, there's no air, no aerobic bacteria, and therefore different filtering
properties, which may or may not be adequate.

I'm not a hydrologist, but I know that the situation can vary tremendously
based on the type of soil, water table level, and so on.  It's likely that
the drywell solution is perfectly acceptable in many circumstances.  Or perhaps
piping the runoff towards a storm sewer is the right solution, if the sewer
system has a treatment plant that expects to filter out chemicals.  

Strictly speaking, the neighbor in this case shouldn't be doing anything to
cause increased runoff onto another persons property.  Forcing the issue is
tough, so my initial inclination would be to grade the property line so that the
runoff heads back onto the neighbor's property, making it his problem :-).  
That's difficult, too, but a more realistic approach, in some circumstances 
(emphasis on the some), would be to put in swales to try to spread the runoff
over as large an area as possible.  At least, that's what I'd try, but I don't
think I can be telling other people what to do.

I'd also make an attempt to find out how high the water table is in the area.
If it's far down, I'd worry less about the drywell, but if it's high up,
I'd think seriously about spending the bucks to get an opinion from a hydrologist
or CE.  If it's really high up, then there probably isn't too much you can do,
other than putting in a pond.

   Gary
192.24SASE::SZABOIn fact, it's a gas!Tue May 07 1991 11:5717
    Thanks for all replies.  Lots of great info and I obviously have to
    carefully think about what I'm doing here.  The major factors in my
    case are #1 the clay soil which I have no idea just how deep it goes
    before I hit a `different' soil layer, #2 we are in a high water table
    since the Merrimack River is a matter of only 2-3 football field
    lengths away, plus lots of wetlands adjoining/within our development,
    and #3 adding soil to complete my backyard landscaping will surely
    flood out my next door neighbor...
    
    As much as I'd love to solve this problem with a drain and/or drywell,
    the thoughts of DIYing it is as scary as every brewery in existance
    going out of business.  In fact, the $1k estimate to dig a huge drain
    is looking mighty attractive, but I just don't have that kind of money. 
    I'll look harder at diverting the runoff first...
    
    Thanks again,
    John
192.25Need sump pit dimensionsCSDNET::DICASTROjet ski jockeyTue Aug 18 1992 15:1913
    This is a (mis-directed?) sump pit question.
    
    How large should a sump pit be ?
    
    I put in the perimeter drainage system due to hydrostatic pressure, and
    a high water table, works GREAT, but the sump piy is a 5 gal. bucket,
    and the pump has a tiny cycle time, on for 2 sec. off for 5 -repeat...
    when it rains.
    
    So I want to put in a larger pit, is the a formulae or a rule of thumb
    
    thank you 
    -bob-
192.26JUPITR::HILDEBRANTI'm the NRATue Aug 18 1992 15:289
    Re: .25
    
    Never saw a formula....size would be that which makes the pumping
    cycle reasonable....yours is too small (you knew that). I would
    find something that has walls and no bottom.
    
    My first house used a clay flue liner....8X12 and about 3 feet deep.
    
    Marc H.
192.27RAMBLR::MORONEYIs the electric chair UL approved?Tue Aug 18 1992 16:089
I would think if you doubled the capacity of the pit the "on" and "off" time
will double.  Note it is the capacity between the "turnoff" and "turnon
levels, not total capacity.

Also, you may be pumping the same water repeatedly by having it backflow
into the pit with the pump off.  A check valve in the outlet line will
stop this.

-Mike
192.28of pits and check valves...KEYBDS::HASTINGSWed Aug 19 1992 16:5021
    Whoa! Mike! I never thought I'd have to correct *you*. Beware of
    putting a check valve in the outflow line. If the outside end of the
    line ever freezes you could be a very unhappy camper. If you insist in
    the check valve just make sure that any water left in the line because
    of the valve is not close enough to the outside to freeze.
    
    
    	As regards the pit size - you may want to talk to the manufacturer
    of the pump that you select. There is an optimim cycle time for every
    motor. Run them too little and the lubricant will dry out and cause
    premature failure. Run them too much and you will also risk premature
    failure. I learned this from my Civil Engineer for my septic system.
    The manufacturers publish graphs that allow calculation of the optimim
    duty cycle to maximize motor life. The trick is to estimate the volume
    of water that you need to move. If you can do this and have access to
    the proper graph for your pump you should be able to calculate the
    optimum pit size for your situation.
    
    
    
    
192.29My SolutionJUPITR::HILDEBRANTI'm the NRAWed Aug 19 1992 17:2217
    Re Check valve
    
    The first sump pump set up that I had, had NO check valve at all.
    When the pump shut off, the water was drawn BACK into the pit from
    where I had dumped it; because the pit was lower than the water...
    siphon effect.
    
    As I watched the water flow back in/out/in/out.....I just knew that
    I had to do something! I drilled a small hole into the plastic 90
    degree elbow that was used to fasten the two sections of plastic
    pipe. This elbow was at the highest part of the water route.
    
    When the pump was on, a small stream came out. When the pump turned
    off, the water drained out of the pipe, to where it was to go.
      ****CHEAP SOLUTION***
    
    Marc H.
192.30RAMBLR::MORONEYIs the electric chair UL approved?Wed Aug 19 1992 19:5222
re .28:

Yeah a check valve in a place where there could be a freeze would be a poor
idea.  But if this is in a place where it can't freeze such as a full basement
it may still be a good idea if there is a large volume of water in the vertical
rise pipe.  If this volume of water exceeds the volume in the sump between
the high and low water cutoffs, the pump could repeatedly cycle on and off,
repeatedly pumping the same water, and never actually accomplish anything.
If the volume is close the pump will cycle more than it needs to to pump
some water.

The check valve is best located close to the pump, so the water in the pipe
is pushing it closed when the pump is off.

One way to avoid a check valve is to use a smaller diameter outlet pipe, which
will reduce the backflow into the sump , but be sure the diameter is large
enough to handle the pump's flow.

A small hole, or better yet a siphon breaker at the top is also an excellent
idea, and may eliminate the need for any check valve.

-Mike
192.31Lint clogged drywellJUPITR::DJOHNSONGreat is His FaithfulnessTue Jan 26 1993 16:286
    I have a 10' drywell for the gray water from my washing machine.  After
    15 or 20 years of use it seems to be clogged up with lint.  Any ideas
    on how to clean it out short of digging it up?  I've already resignd
    myself to that but would prefer something easier.
    
                                             Dave
192.32backflushELWOOD::DYMONWed Jan 27 1993 09:5012
    
    Dave, where do you live?  I have a back hoe and could use the
    money!!...:):):):):)
    
    Depending on how clogged it is....you could try flushing it.
    Borrow or rent a trash pump and dump a lot of water in.  Pump
    it out until its almost dry and then turn on the water (garden
    hose) and try to wash the walls off.  If its only scumed over
    on the inside, it might buy you some time.  But if its packed
    into the soil..............
    
    JD
192.33Drywell DEconstructionSTRATA::PROWELLThu Apr 15 1993 16:4713
    What I have are some old drywells at each corner of my foundation. 
    There is only one still attached to a downspout.  The others are "just
    there"  I am having new gutters put on with downspouts of ample length
    to drain away from the foundation.  
    
    My question is, should I dig these things out and fill them up.  I know
    one corner leaks like a spring through the rock foundation.  The one
    with the downspout still attached is the one which leaks the least into
    the cellar.
    
    Thanks.
    
    Laura
192.34JUPITR::HILDEBRANTI'm the NRAThu Apr 15 1993 17:383
    Fill them in.
    
    Marc H.
192.46INSTALLING A DRY WELL?AKOCOA::HRYANTue Nov 23 1993 18:5410
    Can anyone tell me how to install a dry well?  We currently have a 
    water softner that runs into our septic system.  Our neighbors have
    just informed us that they have to replace their entire leach field
    due to the water softner ruining it. They were told that the water 
    softner should have been drained into a dry well.
    
    Thanks,
    
    Holly
    
192.47quick drainELWOOD::DYMONFri Dec 03 1993 10:3511
    
    
    I'd first check with the town to find out if you can
    install a drywell.....
    
    if its ok.....dig a good size hole(depending on how much water
    is to go into it and soil conditions), place some drain tiles in
    and fill around it with stone.  Put your cover on and presto'.  A
    drywell....
    
    JD