Construction Studies Portfolio, Leaving Certificate 2010- Layout of a septic tank.
-
Upload
keyron-hen-der-sun -
Category
Documents
-
view
9.397 -
download
1
description
Transcript of Construction Studies Portfolio, Leaving Certificate 2010- Layout of a septic tank.
2010
Exam no: 115909
2/21/2010
Lay Out of a Septic Tank
Construction Studies Portfolio
2
Foreword
This document has been compiled by Ciaran Henderson as part of his 6th year construction studies
course, all rights reserved®. If you would like to find out more about Ciaran;
His LinkedIn Profile:
His O-Desk Profile:
3
Contents
1. Project Planning Pg4
2. Research and Investigation Pg6
3. Design Of Artefact Pg11
4. Realisation-Manufacture of Artefact Pg15
5. Evaluation Pg21
6. Experimental Work Pg23
7. Appendix Pg29
4
Project Planning
Introduction to project-
I plan to do primary research by talking to my father as we had a septic tank installed
in 2005 and i plan to investigate whether or not the plans he had would be satisfactory
to base my project on.
I plan to do secondary research on the internet to find out about different kinds of
septic tanks & their different uses.
Aims & Objectives for project-
I aim to achieve an A1 in my project to go towards points for my Leaving Cert.
I aim to have a greater understanding of how a septic tank works so then i can apply
this to my exam if this area comes up.
I aim to apply my skills of planning, organizing and controlling to achieve the best
possible effect that my project makes.
Time Management Strategy-
Septemeber→October: Planning stage
October→February: Construction stage
February→April: Write up stage
Time Management
Write Up
Construction
Planning
5
Budget & Material Constraints-
Wood- Woodwork room for large pieces & home for offcuts.
Plexiglass- Construction room.
Insulation- Left over offcuts from attic conversion at home.
Gravel- Spare bags are in the shed at home.
If required io have allocated €25 for additional materials.
6
Research & Investigation
Analysis of project-
Project Brief:
My objective in this project is to create a 1:100 scale model of a septic tank,
percualation area and my adjoining house. The purpose of the house is to show the
septic tank and perculation area in perspective to it. Because of my project i hope
people will learn from it and gain a greater understanding of septic tanks.
Information needed:
-An understanding of how a septic tank works.
-Information on how to install a septic tank.
-Dimensions of the layout of the septic tank & perculation area.
-Dimensions of a house to compare the septic tank with.
Theoretical Investigation of project area-
How a septic tank works:
1. Sewage enters via the inlet T pipe and
discharges to the lower of the tank.
2. Gravity pulls the solids in the sewage to
the base and via anaerobic biological
action, a scum layer can form on the
surface.
3. Effluent (with a very low solids
content) leaves via the outlet T pipe.
This can then enter a second or third
chamber and then leads to a soakaway
field drainage system(percolation area)
7
Types of Septic tank systems:
Gravity septic system
This is the basic system septic system used.
Wastewater enters the septic tank at the T-inlet,
the sludge settles in the tank and the scum floats
to the top. The effluent then flows out of the tank
to the drainfield/Percolation area.
Septic tanks may have one or two compartments .
two compartments do a better job at settling solids
and are required for new systems.
Tanks need to be emptied every 3-5 years,
depending on the tank size, the amount and type
of soilids entering the tank.
Early warning levels inside the tank-
-The bottom of the scum layer is within 3 inches of
the bottom of the outlet tee or baffle
-the top of the sludge layer is within 12 inches of the
bottom of the outlet fitting.
The percolation area is a network of
perforated pipes laid in gravel filled
trenches. Effluent trickles out these
pipes, through the gravel
& into the soil. The
size and type of each
depends on the daily
wastewater flow &
soil conditions.
8
Pressure distribution septic system
This is used in areas where the conventional
system cannot ensure safe water treatment. It
allows for-
1) Resting cycles.
2) Equal distribution of effluent.
3) Shallow placement of drainfield.
This system works essentially the same way
as the Gravity system, other than it contains
another chamber with a pump that
electronically controls the flow of effluent to
the drainfield. It does this using “control
floats” when they reach a certain level
specific amounts of effluent are released.
This system also has an alarm float
that when levels get too high in the
tank it alerts the household, this
prevents a build up of dangerous
gasses and stops overflowing saving
costs on emergancy call outs.
Mound septic system
These are essentially the same as a
pressure distrubution system other than
the percualtion area is rasied up on a
“mound” of sand with a gravel filled
bed.
These are used in areas where the
ground is not suitable enough for
drainage and so is raised up. This gives
the effluent a greater distance to travel
before reaching groundwater.
9
Sand septic system
These are essentially the same as a pressure
distrubution system other than the extra
sand filter which allows for a high level of
wastewater treatment.
The sand filter is filled with specific sand
material, a network of pipes is placed in a
gravel-filled bed ontop of the sand. The
septic tank effluent is pumped under low
pressure through the pipes in controlled
doses to insure even distribution. The gravel
underdrain then collects the effluent and it
travels to either a second pump for
discharge or to a gravity flow drainfield.
Aerobic Treatment Unit
ATU’s are similar to standard septic
systems in that they use natural processes
to treat wastewater. But unlike
conventional systems, ATU’s also use
oxygen to break down organic matter.
These units have a main compartment
(aeration chamber) in which air is forced
and mixed with the wastewater. This
creates an environment where bacteria
are free-floating in the liquid and grow as
they digest the solids.
Many units include a second chamber where
solids, that the bacteria are unable to digest,
settle. The two chambers are connected, so these
undigested solids can be returned to the aeration
chamber, either by gravity or a pump. It is this
process of return and mixing that is important for
effective operation.
10
AdvanTex-AX Wastewater Treatment System
Instead of using sand
or gravel for the
filtering media, the
AdvanTex product
line uses an
engineered textile.
Textile is much more efficient than sand or gravel
because it has about five times more surface area. That's
why, with textile filters, you can treat the same amount
of wastewater in a fraction of the space.
Drip irrigation
This is a shallow, pressure-dosed system that equally
distributes pre-treated wastewater at a slow rate over
the entire drainfield, preventing saturation of the soil.
This is not so much a septic tank than a way to reuse
wastewater from a source such as septic tank effluent. This is
a very effective way to use wastewater as leveling the field is
not nessesary, you have the ability to irrigate irregular shaped
fields & there is a lower labour cost in maintaining this system.
11
Design of Artefact
Design idea for artefact-
My inspiration for this project came from my personal life experiences.
In October of 2000 me and my family moved into a new house in newtownmountkennedy,
Co. Wicklow. The house at first
seemed fine, just in need of a few
minor repairs and spruce ups, however
we soon discovered that the toilet was
backing up due to a horrible
“homemade” septic tank that was
installed when the house was built.
Because of this the toilets kept backing
up and there was a terrible stench both
outside and inside the house. We had
to replace this with a brand new septic
tank system at a cost of about €10,000.
The construction of this new septic tank took over 3
months to complete and the contracters had to dig up our
entire back garden to install it. The septic tank itself was
about 10ft in height and had to be lifted into place with a
crane.
The first step in the construction process was to dig a test
hole to determine the drainage ability of the garden. After
this was completed they could begin to dig the
trenches for the perculation area and the hole for
the septic tank.
They then laid gravel into the trenches for the
pipes and in the excavation for the septic tank and
around the tank. These trenches were then covered
over and buried. The septic tank was then
manovered into place in the ground, and buried
other than the diffusion inspection chamber for the
settlement chamber and the inspection chamber for
the air compressor.
12
My original idea was to do a cut-through section of a septic tank and show all the inner
workings of it.
However i decided against this as i
could not visualise the end reslult
or see what materials i would
require to carry out this kind of
project. I also thought it would end
up being quite intricate and small.
My next idea was to do a 1:1 scale of a perculation pipe and
surrounding area, show all the different aggregate layers and
the different distances required to achieve good drainage and
to meet regulations. However i didnt use this project idea as i
thought that-
a) It would end up being far too big.
b) It would not be very interesting to construct/examine.
c) It would not be much of a challenge for me.
The idea i finally decided on was
to do a model of the layout of a
septic tank and perculation area as
this would present more of a
challenge for me, would be
interesting to look at and would
aid me in my exam if a scale
drawing happened to come up.
I decided to do this model at a
1:100 scale.
13
Working Drawings and design drawings for artefact-
Plan of septic tank & perculation area aquired from Architecht-
Cutting List-
Baseboard: 297 × 420 (size of an A3 sheet)
Plexiglass-2x 420mm x200mm
-2x650mm x20mm
14
Template-
This will be used to measure
the length & position of the
wires when cutting them to
represent the pipework of the
perculation area.
This will also be used to mark
out the location of the trenches
to be dug for this pipework.
This will also be used for the
location of the septic tank
relevant to the perculation
area.
15
Manufacture of Artefact
Preparation of Materials-
Measuring the base board to the correct size (x)
Measuring the plexiglass to the correct sizes (650x200) x2 and (420x200) x2.
Aquiring of 3 different grades of aggregates -Large→ From my garden.
-Medium→ From my Driveway.
-Small→ From my dads work.
Aquiring sand from my garden.
Aquiring soil from the school grounds.
Marking out-
Used a set square & pencil to mark
out the measurements on the
baseboard.
Used a red whiteboard marker to
mark out the different levels of
aggregates stone/sand/soil.
Marked out the position for the
screws with a gel pen 5mm up from
the bottom of the baseboard and at
equal intervals apart.
Processing of parts-
I pre-drilled holes through the bottom of each of the pieces of plexiglass so as the
screws would fit into them smoothly & tightly.
I then counter sunk each of these holes so as the screws would sit flush with the rest
of the plexiglass & would not be unsightly.
Got the teacher to cut the baseboard on the bandsaw for me so it would be perfect.
16
Assembly-
Step 1
Glued the edges of the baseboard &
got a fellow student to help me.
While he held the plexiglass against
the baseboard one-by-one i drilled
the screws through the pre-drilled
holes in the plexiglass into the
baseboard.
Glued each of the corners of the box
up to the top so the corners would
stay together.
Clamped it so it would dry in place.
Step 2
Placed a block of styrofoam in the
center of the box to-
A) Take up room so i would not
need as much stone.
B) Make my project lighter.
I then filled the bottom of the box
with my first large stone aggregate
up to the first red marking.
17
Step 3
Firstly placed the 2nd layer of
aggregates into the box(small
stones) up to the red line &
ensured it was even all the way
around.
Ontop of this I placed the 3rd
layer of aggregates into the
box(small gravel) up to the next
red line.
Step 5
I then placed the next layer
of aggregates into the box
(sand)
I used a broad flat piece of
wood to scrape across the
top of the sand to ensure it
was flat and even.
18
Step 6
For the final layer of
aggregates i used a shoval to
collect soil from the field
beside my school.
I then distubuted this soil
evenly on the top of the
previous layer of aggregates.
Step 7
Cut up and glued together wiring
to the scale and size of the pipes.
Cut out a template & used it to
dig scale trenches in the correct
location.
Used a kinder egg as a scale
septic tank as it happened to be
the right size, painted it
green and put it in
place.
<-Template
19
Step 8
Cut pieces of wood to scale to the size
of my house. Nailed/glued the pieces
together.
Painted the house grey.
Using a pencil and a ruler drew scale
bricks onto the house.
Using a hammer, tacked felt to the top
of the house and trimmed it with a
stanley knife.
Cut scale batons and super-glued them
onto the top of the roof.
Using a chisel and mallet I cut up a
large piece of slate into scale slates.
I then superglued these slates in place
in 3 rows.
Finishing-
To finish off the project i
made small signs to be placed
around my project to
highlight important sections,
such as the septic tank,
perculation area and the
location of the house.
I also wiped off any of the red
marker that was left on my
project, earlier used to find
the height each of the
aggregates were going to
come to.
20
Modifications-
Took place after step 3
I noticed that the glue i placed on the corners
of the perspex in step 1 was not holding all the
weight in the box together and it was starting
to come apart.
I therefore cut 4 small pieces of wood to fit
into the corners.
I then pre drilled holes in the perspex and
counter-sunk them.
Then I drilled 2 screws into each of these
wooden pieces to tighten the box up.
21
Evaluation of Project
Critical Appraisal of Project
The original plan was good, and if i had
of followed it more strictly my project
may have turned out better.
I should have had more foresight to
recognise in the manufacturing of the
project in step 1 that the glue I placed
on each corner would not be enough to
hold both the perspex box and its
contents in.
The step I took to attempt to rectify the
problem, i see now, was not sufficient
enough to keep the box satisfactorily
together, as each of the walls of the
perspex box began to split and come
apart.
If i was to do the project again, i would
have placed a piece of wood all the way
from the bottom to the top in each
corner, glued and screwed this to the
perspex so it would not come apart.
I now realise that the scale of 1:100 I
manufactured the project to is far too
small and if i was to repeat this project
i would make the scale 25% larger and
increase it to 1:75 so i could put more
detail into the septic tank &
perculation area.
As it is the scale was too small to
include things like-
Gravel around the perculation
pipes.
Detail in the septic
tank(chambers, vents)
The perferations in the perculation pipes.
22
Personal Reflection
I enjoyed working on my project overall and especially enjoyed being able to use my hands
to create something that could be used to aid someone educationally.
I also managed to learn-
How to layout a percualation area and septic tank.
How to use many tools, including- chisel, mallet, hammer, drill and a stanley knife.
How to manage my time and keep to a schedule.
How to use many different substances such as- superglue, woodglue & paint.
I really enjoyed doing the experiments too as i got to see how things worked in a more
practical way and really improved my understanding of aggregates, how they behave and
how they may be used.
Although i enjoyed doing the project and am happy with the end result i dont think that the
amount of effort I put into my project is reflective of the amount of marks being awarded for
it. The fact that the manufacture of the artefact is only worth 8% of the total marks awarded
for construction studies is not really a fair reflection of the work put in.
Completed Artefact
23
Experimental work-To Test DPC
Introduction
In this experiment i will be determining the ability of DPC and
proving that it functions and prevents rising dampness and eventual
damage to a structure. This experiment was carried out between the 22nd of march
& the 23rd of march 2010.
Preparation & Planning
Ensured that i had permission from Mr. Bergin the construction studies teacher to
carry out this experiment in the construction room and leave it there overnight.
Materials Needed-
1 large breeze block.
2 standard bricks.
Equipment Needed-
Basin
Scales
I plan to-
-Place 1 large breeze block into a basin and fill up the basin to cover ¾ of the block.
-Place block A straight ontop of the large block to use as a comparison.
-Place block B ontop of the breeze block with DPC between the surfaces to prevent
contact.
-Weigh the blocks at the start, at 12hours and at 24 hours to compare.
Procedure
1. Place large breeze block into the
basin.
2. Fill the basin until it covers ¾ of the
large breeze block
24
3. Place block A directly ontop of the large
breeze block to use as a comparison
4. Place DPC ontop of the large breeze block
to the right of block A
5. Place block B ontop of the DPC ensuring
that none of the block comes into contact
with either the breeze block or block A.
6. Record the weight of both
blocks after 12 hours and after
24 hours
Health and Safety-
Ensure the test is carried out in a isolated location to prevent tripping or spillage.
Follow all safery rules in the Construction room.
Results
Conclusion & Evaluation Of Results
The results of my experiment showed that block A(without DPC) gained 42grams in weight
in a 24 hour period, while block B actually lost weight-i have determined this was because
the block still retained moisture from being outside & dried out while inside. This proves that
DPC not only works but is essential to all buildings as over time this rising dampness would
severly damage the structural integrity of a building.
Comments
If i was repeating this experiment again i would have allowed the bricks to dry out properly
before carrying out the test and i would have tested a few different materials (wood, cement,
metal) to see which material carries the water fastest.
Origonal Weight After 12 hours After 24 hours Weight change
Block A 2537gms 2569 gms 2579gms +42gms
Block B(DPC) 2894gms 2894gms 2891gms -3gms
After 24-hours
At start
25
Experimental work-Silt Test
Introduction
In this experiment i will be determining the percentage of silt in a sample of sand
using a formula.
Preparation & Planning
Talked to Mr. Black the physics teacher and organised to do the experiment in the physics
lab on the 25th Jan 2010 at 1pm.
Materials Needed-
100ml Water.
50gms of sand.
Equipment Needed-
Graduated cylinder.
Trowel.
I plan to-
Show that over time silt will form ontop of sand
when left to settle. I will also show the
percentage of silt in the sand.
Procedure
1. Fill the graduated cylinder with 50ml of water.
2.Fill the Cylinder until the
level reaches 100ml.
3. Place 50ml of water in cylinder so it
reaches 150ml altogther.
26
4.Shake the Cylinder vigourously and leave to settle.
5.Take measurements after 1hour and 2hours.
Health and Safety-
Ensure the test is carried out in a place where no-one will spill the
contents.
Results
Height of silt layer
Height of sand layer
5
75
Conclusion & Evaluation Of Results
The results of my experiment showed that when left to settle silt does
indeed form ontop of sand. Although the level of silt may be very small it is
significant enough to measure easily enough.
Comments
If i was to do this experiment again i would use a larger graduated cylinder and i would
double the amounts of sand and water so as to get a more accurate result and i would also
record the heights every half hour instead of every hour- this should also ensure a more
accurate result
After 1 hour
X100 = % of silt
After 2 hours
X100 = 6.6 % Silt
27
Experimental Work-The Moisture Content Of Aggregates
Introduction
In this experiment i will be showing the moisture content of aggregates(sand) by
heating it up in a cylinder using a bunsun burner.
Preparation & Planning
I carried out this experiment on the same day as the previous experiment of the 25th
January 2010 at 3pm.
Materials Needed-
1kg of sand
Equipment Needed-
Bunsen burner
Cylinder
Stand
Timer
Weighing scales
I plan to-
Show the moisture content in the sample of sand i have for this
experiment.
Procedure
1. Place 1 kg of sand into the graduated cylinder(it weighs
261g)
2. Heat up the sample of sand and stir it.
3. Measure the weight of the
sand every 30min until the
weight doesnt drop anymore.
After 30 min
28
4.Place results in a table.
Health and Safety-
Ensure safety glasses, overalls and gloves are worn.
Ensure the utmost care is taken when heating the
cylinder.
Ensure gas is switched off at the mains once finished.
Results
Time Weight Change
Start 1261grms
30min 1251 grms 10 grms
60min 1240 grms 11 grms
90min 1225 grms 15 grms
Conclusion & Evaluation Of Results
Wet weight-dry weight
Dry weight
1261-1225
1225
Comments
The test did indeed show the moisture content of the sand but at
a very low level. If i was to do the experiment again i would use
less sand to speed up the process of drying as i think i did not
dry the sand in this experiment quite long enough.
I would also try different types of aggreagates such as soil, gravel and pebbles.
After 1 hour
After 1 ½ hours
X100 = % of moisture content
X100 = 2.9% moisture content
29
Appendix
All the following photos were taken by me or my father-
Pg 6- Trench.
Pg10- The septic tank.
Pg13- The template.
Pg13→19 The manufacturing of my project.
Pg20→25 Photos of my experiments.
Pg26→27 Evaluation photos.
All other images throughout the portfolio are thanks to http://www.google.ie/images