Home Repair forum - Drain field design and "As Built" drawings

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Drain field design and "As Built" drawings

Eigenvector

2006-06-29, 9:28 am

I recently requested an "As built" drawing from my county health department
for the septic system. What they faxed back to me was not exactly what I
was expecting to see. It was dated 1960 and listed the owners, builders,
and inspector.

I happen to have a degree in engineering and I was expecting to see an
engineering drawing or something official (maybe even on vellum) - what I
got was best described as "back of the napkin with a coffee ring as a bonus
decoration". First, is that realistic, I don't want to harp on it if in
fact that's what they're all like, and second how truthfully can I take the
measurements and layout of the "drawing"?

I'm looking at the drawing and it looks like they deliberately routed the
drain field so that it goes off in weird angles, makes several beelines for
the massive Douglas Fir in my backyard and otherwise doesn't efficiently
utilize the space provided for it. I was expecting a nice layed out route
involving 90 deg bends and long branches. What I see is the first line
making a large oblique angle into the middle of the yard then sending
branches back toward the tree, finally connecting back to itself after
circling the tree.

Was it common to design the field to incorporate trees as a means of
absorbing water?

tbasc@bellsouth.net

2006-06-29, 9:28 am

Eigenvector wrote:
> I recently requested an "As built" drawing from my county health department
> for the septic system. What they faxed back to me was not exactly what I
> was expecting to see. It was dated 1960 and listed the owners, builders,
> and inspector.
>
> I happen to have a degree in engineering and I was expecting to see an
> engineering drawing or something official (maybe even on vellum) - what I
> got was best described as "back of the napkin with a coffee ring as a bonus
> decoration". First, is that realistic, I don't want to harp on it if in
> fact that's what they're all like, and second how truthfully can I take the
> measurements and layout of the "drawing"?
>
> I'm looking at the drawing and it looks like they deliberately routed the
> drain field so that it goes off in weird angles, makes several beelines for
> the massive Douglas Fir in my backyard and otherwise doesn't efficiently
> utilize the space provided for it. I was expecting a nice layed out route
> involving 90 deg bends and long branches. What I see is the first line
> making a large oblique angle into the middle of the yard then sending
> branches back toward the tree, finally connecting back to itself after
> circling the tree.
>
> Was it common to design the field to incorporate trees as a means of
> absorbing water?

You should consider yourself lucky that the building department found a
45 year old drawing.
In many parts of the country, no records were made or kept accessible.
TB

buffalobill

2006-06-29, 9:28 am

i don't know, but you're lucker than i am.
some government employees were told to clean out an old room and threw
away filed and approved building plans in an old storage room in
buffalo ny city hall back in the 1960s including some of mine from the
1910 era.
in your case hidden underground rocks and the number of years that have
gone by are other factors besides lost memories of former owners as to
where all the pipes are.
your thirsty tree probably has also enjoyed free fertilizer from your
system for many years.

Eigenvector wrote:
> I recently requested an "As built" drawing from my county health department
> for the septic system. What they faxed back to me was not exactly what I
> was expecting to see. It was dated 1960 and listed the owners, builders,
> and inspector.
>
> I happen to have a degree in engineering and I was expecting to see an
> engineering drawing or something official (maybe even on vellum) - what I
> got was best described as "back of the napkin with a coffee ring as a bonus
> decoration". First, is that realistic, I don't want to harp on it if in
> fact that's what they're all like, and second how truthfully can I take the
> measurements and layout of the "drawing"?
>
> I'm looking at the drawing and it looks like they deliberately routed the
> drain field so that it goes off in weird angles, makes several beelines for
> the massive Douglas Fir in my backyard and otherwise doesn't efficiently
> utilize the space provided for it. I was expecting a nice layed out route
> involving 90 deg bends and long branches. What I see is the first line
> making a large oblique angle into the middle of the yard then sending
> branches back toward the tree, finally connecting back to itself after
> circling the tree.
>
> Was it common to design the field to incorporate trees as a means of
> absorbing water?

Nonnymus

2006-06-29, 9:28 am

I'd guess that probably 80% of the homes standing today were
built from plans with three sheets: Elevation,
basement/foundation and floor plan. Most lumber yards had
draftsmen who would draw up house plans for free if you
bought your lumber from them. Until lately, only big cities
had inspectors. My own home town finally got an inspector
in the late 1960's, and he was (theoretically) responsible
for everything including plumbing connections to the water
and sewer, septic, electrical and finished.

Outside of big cities, which had subcontracting, most
small-town generals had crews that set the footers and
basement forms, framed and did everything. Through the
60's, my Dad had a 6-man crew that built darned good houses
and the only subs were for excavation, plumbing, HVAC and
drywall. I did most of his electrical, we all pitched in on
the drywall and flatwork, painting, roofing etc. Besides
being a darned good education for a teenager, it also
produced a very responsibly constructed house.

If a house had a septic system, the old boy with the backhoe
was the one who laid it out from the seat of his backhoe.
IMHO, most of those old systems are probably as good as the
engineered ones, but if something DID go bad, it really went
bad,

Nonnymus

Eigenvector

2006-06-29, 9:28 am

"buffalobill" <wjohnston@adelphia.net> wrote in message
news:1151548941.655875.126810@y41g2000cwy.googlegroups.com...
>i don't know, but you're lucker than i am.
> some government employees were told to clean out an old room and threw
> away filed and approved building plans in an old storage room in
> buffalo ny city hall back in the 1960s including some of mine from the
> 1910 era.
> in your case hidden underground rocks and the number of years that have
> gone by are other factors besides lost memories of former owners as to
> where all the pipes are.
> your thirsty tree probably has also enjoyed free fertilizer from your
> system for many years.
>

Aren't trees bad for the drain field though? It is conceivable that the
tree grew after/at the time the house was planted, maybe even the
construction helped bury the seed that spawned the tree?? I don't know, but
it's definitely around 40 years old, its a BIG tree but then again Douglas
Firs grow pretty fast. I ought to scan in the "As built" to show you how
primitive it is, although if the responses here are any indication its
extremely well crafted by comparison - heck it's on graph paper! Still, I
have to wonder about the crazy angles and poor overall layout of the drain
field.

If/When the city does finally incorporate my development and routes sewer
through the neighborhood, do I have to do something to deactivate the septic
system? Can I just dispose of the tank, re-route the sewer line, then let
the trees and bushes take care of the drain field?

> Eigenvector wrote:
>

kevin

2006-06-29, 9:28 am

The "as built" drawing sounds at least as good as the one I got, from a
system put in not 5 years ago by the previous owner. It is a piece of
letter-size paper, with some blanks at the top (address, date,
contractor, etc.), a few signatures at the bottom, and a hand-drawn
figure in the middle. At least they used a ruler.

It isn't to scale, the angles are all just sort of approximations, the
distances are completely wrong, the landmarks they picked to do a
triangulation no longer exist (a fence post and a bush? come on! both
corners of the house are right nearby and could have been used easily).
Not to mention that the triangle is so acute that even if the distances
were correct, the +/- a few inches makes the location swing about +/-
10 feet.

I ended up just doing some digging, some poking around, and found most
of the lines. I then took some pictures from an upstairs window, and
overlaid lines on the (digital) picture with measurements. (As for
poking around, if your's is very shallow, like mine... I took a piece
of 4-foot rebar and went out after some very heavy rain. I was able to
poke it in by hand about 2 feet, deep enough to feel the gravel in the
drain field, and was lucky enough to hit and locate a few pipes that
way too.)

Eigenvector wrote:[color=darkred]
> "buffalobill" <wjohnston@adelphia.net> wrote in message
> news:1151548941.655875.126810@y41g2000cwy.googlegroups.com...
>
> Aren't trees bad for the drain field though? It is conceivable that the
> tree grew after/at the time the house was planted, maybe even the
> construction helped bury the seed that spawned the tree?? I don't know, but
> it's definitely around 40 years old, its a BIG tree but then again Douglas
> Firs grow pretty fast. I ought to scan in the "As built" to show you how
> primitive it is, although if the responses here are any indication its
> extremely well crafted by comparison - heck it's on graph paper! Still, I
> have to wonder about the crazy angles and poor overall layout of the drain
> field.
>
> If/When the city does finally incorporate my development and routes sewer
> through the neighborhood, do I have to do something to deactivate the septic
> system? Can I just dispose of the tank, re-route the sewer line, then let
> the trees and bushes take care of the drain field?
>

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