Dry Well Pump Station Construction: A Case Study of Lee Tunnel

This paper focuses on the construction of the dry well pump station while making reference to the Lee Tunnel of London. It highlights the possible shortcomings within Lee Tunnel in regard to the civil work and proposes solutions. The paper discusses the design, construction, and operation of the dry well pump station. It also identifies the possible risks associated with the operation of such wells and measures to ensure environmental safety and protection.

ENGINEERING RESEARCH AND PLANNING
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Abstract
Pumping stations are known to be
responsible for handling sewage either as in
the pumping line from a deeper sewer to
shallow sewer or conveying the same
component to STP. In certain configuration
of the well design, the STP is the outfall
itself. Such system will therefore be required
where the system of the sewerage from the
areas of low lying development is not able to
drain its content by the means of gravity.
Also it may be needed where development
are in too remote areas from the available
infrastructures of the sewerage. This
particular paper focuses on the construction
of the dry well pump station while making
reference to the Lee Tunnel of London.
Key Words: CFD, Dry well pumping
station, Lee Tunnel
Introduction
The waste water dry well pumping stations
which are available in most of the places
constitute a sealed device which is complete
to be used in the sanitary transportation of
waste water, water from the municipal
drainage or water which has been sourced
from dewatering at greater distances. In
some occasions, it has been used in rising of
water to higher levels1. This makes them
suitable to be used in the gravity-discharge
systems. In such systems, waste water flows
through a drain-house or section of the
gravitational system of sewerage directly
into the tank before it can be pumped
through the pipes by the use of a dry pump
into the collecting well which is located on
the main manifold sewerage. The waste
material can be pumped directly into the
waste water treatment plant.
Considering that there is no need for the
maintenance of zone of protection, the
devices described can just be installed in the
same places in the form of basements, dry
1 Fernandez-Moguel, L. and Birchley, J., 2015. Analysis of the
accident in the Fukushima Daiichi nuclear power station Unit 3
with MELCOR_2. 1. Annals of Nuclear Energy, 83, pp.193-215.

chambers among others. Lee Tunnel is part
of the Thames Water’s London Tideway
Improvement plan. This particular scheme is
believed to be responsible for returning
River Thames to cleanliness level which is
acceptable come 20232. The scheme of the
improvement consists of three projects
including upgrade to the five main treatment
works which are found along River Thames.
Tideway pumping station is at the heart of
the Lee Tunnel, a 38m diameter by 87m
deep pumping shaft which is located at the
Beckton STW. The main purpose of this
particular component is to ensure that there
is transfer of the volume of the tunnel into
the Beckon for activities of the treatments.
The engineering of the pumping station has
been done in a manner to allow for the
operation under both the future Thames Tide
way Tunnels loads and the Lee Tunnel
flows.
2 Guerbaoui, M., El Afou, Y., Ed-Dahhak, A., Lachhab, A. and
Bouchikhi, B., 2013. Pc-based automated drip irrigation
system. International Journal of Engineering Science and
Technology, 5(1), pp.221-225.
Literature Review
The required improvement to the London’s
sewer system is generated by the Lee Tunnel
through removal of the combined discharge
of sewage and storm water to the lower
River Lee and River Thames. The Tunnel
which is expected to have 7.2m as the
diameter is having its construction at an
average of 75m just below the ground levels.
This is the basis of running 6.9km from
pumping station of Abbey Mills complex in
Stratford to Beckton STW which is found in
the East of London. As the volume of the
tunnel is filled with the flow which enters
the tunnel, there is expected rise in the level
of the three wet shafts.3 The three shafts
include the connection shaft, shaft F at the
Abbey and the overflow shaft.
The wet well for the Tideway Pumping
Station is essentially the Connection Shaft
system which in the whole Tideway system
3 Keppen, D. and Dutcher, T., 2015. The 2014 drought and water
management policy impacts on California’s Central Valley food
production. Journal of Environmental Studies and Sciences, 5(3),
pp.362-377

is regarded as the lowest point. This system
is made up of the course screen whose
clearance is done by grab system and
surface mounted rake. These two shafts are
properly connected by the use of 30m long
concrete which is sprayed and is lined tunnel
with stainless steel liner finish. From the
tunnel of suction, the effluent is directed to
the culvert of suction4. This suction culvert
is found at the center of the base of Tideway
Pumping Station. It is from this culvert that
the flow is presented to Lee Tunnel’s 6
constituting drain down pumps and the main
pumps. The flow is divided at the culvert by
means of stainless steel baffle wall before it
can be presented to the 6 bends of the pump
suction. This particular area or the station
will remain split throughout the dry well of
the pumping station through the wall which
is centrally located. The division is
maintained to as to assist in the creation of a
hardened pumping station whereby failure
4 Keranen, K.M., Savage, H.M., Abers, G.A. and Cochran, E.S.,
2013. Potentially induced earthquakes in Oklahoma, USA: Links
between wastewater injection and the 2011 Mw 5.7 earthquake
sequence. Geology, 41(6), pp.699-702.
of one half of the system will enable full
operation of the other half.
The main risers and pumps
The main pumps are 3.4mW single stage
end-suction super pumps. These kinds of the
pumps have been designed uniquely to meet
the challenging duty of the Lee Tunnel and
more importantly the Tideway Scheme.
Each of these major pumps can effectively
deliver 3000l/s where the design of the
maximum station being maintained at
12000l/s. They are therefore capable of
lifting the flow by almost 88m from the
station of pumping especially basement to
the surface. The pumps individually sit on
the reinforced concrete plinths which is
4.3m high.
Research Gap
Despite the perfect parameters which have
been highlighted by various literature
sources, the pipe work of Lee Tunnel is

never supported by the walls of the shafts5.
This has been considered the case despite
the fact that they are galvanized guide
brackets. The brackets are merely meant for
the containment of the vibrations but not
load bearing functions6. This has left the
possible chances of inundation. Inundation
can possibly result into the major problems
of health and environment is case there is
flushing of the raw sewage to the surface
due to wet well flooding. Also this can be as
a result of the system failure due to fully
submerged switchboards. Inundation can
possibly lead to the occurrence of scouring
around the structure especially for the case
of the wet well and the chamber valves. This
will lead to the potential damage of the
critical components like electrical
5 Lampayan, R.M., Rejesus, R.M., Singleton, G.R. and Bouman,
B.A., 2015. Adoption and economics of alternate wetting and
drying water management for irrigated lowland
rice. Field Crops Research, 170, pp.95-108.
6 Pisinaras, V., Petalas, C., Tsihrintzis, V.A. and Karatzas, G.P.,
2013. Integrated modeling as a decision‐aiding tool for
groundwater management in a Mediterranean agricultural
watershed. Hydrological Processes, 27(14), pp.1973-1987.
switchboard. This particular research work
thus seeks to highlight some of the ways
which can be used to ensure proper
Environmental p protection and safety.
Research Questions
 How can environmental protection
and safety be enhanced in the design
of Dry Well?
 What are the possible risks which are
associated with the operation of such
Wells?
Measures to ensure Environmental Safety
and Protection
In order to ensure that safety and
environmental protection is achieved, the
following measures must be put into the
consideration:
There will be provision of railing around the
entire manhole as well as other openings7.
7 Roy, A.A., Adams, P.J. and Robinson, A.L., 2014. Air pollutant
emissions from the development, production, and processing of
Marcellus Shale natural gas. Journal of the Air & Waste
Management Association, 64(1), pp.19-37.

This will be regarded as a common practice
where covers may be left open during the
activities of the operations as well as where
there is injury to the falling individuals.
There will also be provision of the guard
system around the mechanical equipment
that can possibly come into contact with tye
operator like gears, belt-drivers and other
moving components of the equipment.
Methods for measuring the outcomes
Flow Measurements
Use of magnetic Flow meters: The magnetic
flow meters operate on the principle of
electromagnetic induction. The voltage
which is induced by the electrical conductor
is directly proportional to the velocity of the
conductor8. In this particular case, the
sewage will be the conductor itself. This will
make it suitable for all pipe like settled
sewage; raw sewage return activated sludge,
8 Sivakumar, S.S., 2013. Management Policy of Water Table in
Dry Zone of Sri Lanka to Subsidise the Pain of Non Rice Crop
Cultivators for the Food Productivity Improvement, RJSITM. The
International Journal Research Publications, 2(09), pp.2251-1563.
primary sludge and finally treated sewage.
The kinds of the sewage components are
non-invasive and they are used in nearly all
pipes despite the need of the initial
calibration.
Significance of this measurement
The output from the flow measurement by
the use of the magnetic flow metres will be
treated as the standard 4 mA to 20 mA
signals which will be relayed to the system
of central monitoring. It is from this kind of
the outcomes that the guidance for pump
installation will be achieved. The procedure
for the pump installation will definitely
depend on the manner in which pumps are to
be mounted either horizontally or vertically.
The pump installation which will ensure
environmental protection and safety will
include the following procedures:
Preparation of the foundation as well as
fixing of the bolts of foundation

Fixing of the pumps on the bolts which
belong to the foundations9
Leveling
Grouting
Alignment
The foundation shall therefore be substantial
enough to absorb the vibrations besides
forming a permanent rigid support for the
plate of the base.
Risks Associated with the operations
Although there is several risks which in one
way or the other affects the operations of the
dry well, the main one is the bad smell or
odors which originates from the flowing
sewage system.
How to overcome the odour effects
9 Stoppato, A., Cavazzini, G., Ardizzon, G. and Rossetti, A., 2014.
A PSO (particle swarm optimization)-based model for the optimal
management of a small PV (Photovoltaic)-pump hydro energy
storage in a rural dry area. Energy, 76, pp.168-174.
In order to ensure that this particular risk is
effectively handled, the following method
will be adopted: Adsorption:
This particular technique will involve
passage of a stream of foul gas through a
solid material which is porous commonly
refered to as adsorbent10. It is usually
contained within the bed of adsorption. The
surface of this particular material will be
capable of attracting as well as holding the
adsorbed gases by either chemical or
physical adsorption. The targeted material to
be used may include activated carbon.
Results and Discussions
As per the expectations, the size of the well
will be based on the following:
Flow from the proposed developments as
well as any other developments in the future
10 Yu, Q., Wang, Y., Gao, J., Gao, S. and Flemming, B., 2014.
Turbidity maximum formation in a well‐mixed macrotidal estuary:
The role of tidal pumping. Journal of Geophysical Research:
Oceans, 119(11), pp.7705-7724.

Capacity to receive flows from the areas
surrounding the structure as determined by
the authorities in charge. The volume of the
well will be given by the formula shown
below
V = T × Q/4 in which V : Effective volume
of wet well expressed in cubic metres
T: Time for one pump cycle as expressed in
minutes
Q: Pumping rate (cubic meters per minute)
As a model, the well will be expected to
work with the corresponding capacities
illustrated below:
Capacity of pumping at peak flow= 42 cubic
metre for every minute
Required Volume: = 42/4x15=158 cubic
metres
Possible depth below sewer’s invert=2m
Required area= 158/2= 79m2
Required Diameter=
SQRT(4x79/3.142)=10m11
Significance of the above outcome
The above outcome will be used in real life
design situation of dry well pump station
while putting the concept of scale into
practice.
Competition and ease of implementation
The automatic pump operation will be made
operational by the use of pre-programmed
logic controllers which will be capable of
starting the specified pump set once the
level of the sewage reaches the height which
is specified. This implies that it will be
possible for more pumps to be progressively
brought into operations while reversing the
same trend as the sewerage level drops. It
can be made possible by having an input of
float switch that has contact of mercury in
the sealed float. The float will get tilted to
11 Zhang, J., Liu, J., Campana, P.E., Zhang, R., Yan, J. and Gao,
X., 2014. Model of evapotranspiration and groundwater level
based on photovoltaic water pumping system. Applied energy, 136,
pp.1132-1137

the position which is horizontal and floats
when the level of the swage reaches the
structure itself (float). This will results into
the closure of the electronic circuit within
the float which will be responsible for the
generation of a standard signal of 4 mA to
20 mA conveyed to the control panel hence
the pump is activated12.
Conclusion
The study has effectively identified the
possible shortcomings within Lee Tunnel in
regard to the civil work. Although the
proposed solution is given in model form,
the implementation should take full effect on
the appropriate scale while employing
various fundamental principles of dry well
design and construction
REFERENCES
12 Zhu, J., Hu, K., Lu, X., Huang, X., Liu, K. and Wu, X., 2015. A
review of geothermal energy resources, development, and
applications in China: Current status and prospects. Energy, 93,
pp.466-483. Chen, J., Ganigué, R., Liu, Y. and Yuan, Z., 2014.
Real-time multistep prediction of sewer flow for online chemical
dosing control. Journal of Environmental Engineering, 140(11),
p.04014037
[1] Fernandez-Moguel, L. and Birchley, J.,
2015. Analysis of the accident in the
Fukushima Daiichi nuclear power station
Unit 3 with MELCOR_2. 1. Annals of
Nuclear Energy, 83, pp.193-215.
[2] Guerbaoui, M., El Afou, Y., Ed-Dahhak,
A., Lachhab, A. and Bouchikhi, B., 2013.
Pc-based automated drip irrigation
system. International Journal of
Engineering Science and Technology, 5(1),
pp.221-225.
[3] Keppen, D. and Dutcher, T., 2015. The
2014 drought and water management policy
impacts on California’s Central Valley food
production. Journal of Environmental
Studies and Sciences, 5(3), pp.362-377.
[4] Keranen, K.M., Savage, H.M., Abers,
G.A. and Cochran, E.S., 2013. Potentially
induced earthquakes in Oklahoma, USA:
Links between wastewater injection and the
2011 Mw 5.7 earthquake
sequence. Geology, 41(6), pp.699-702.

[5] Lampayan, R.M., Rejesus, R.M.,
Singleton, G.R. and Bouman, B.A., 2015.
Adoption and economics of alternate
wetting and drying water management for
irrigated lowland rice. Field Crops
Research, 170, pp.95-108.
[6] Pisinaras, V., Petalas, C., Tsihrintzis,
V.A. and Karatzas, G.P., 2013. Integrated
modeling as a decision‐aiding tool for
groundwater management in a
Mediterranean agricultural
watershed. Hydrological Processes, 27(14),
pp.1973-1987.
[7] Roy, A.A., Adams, P.J. and Robinson,
A.L., 2014. Air pollutant emissions from the
development, production, and processing of
Marcellus Shale natural gas. Journal of the
Air & Waste Management
Association, 64(1), pp.19-37.
[8] Sivakumar, S.S., 2013. Management
Policy of Water Table in Dry Zone of Sri
Lanka to Subsidise the Pain of Non Rice
Crop Cultivators for the Food Productivity
Improvement, RJSITM. The International
Journal Research Publications, 2(09),
pp.2251-1563.
[9] Stoppato, A., Cavazzini, G., Ardizzon,
G. and Rossetti, A., 2014. A PSO (particle
swarm optimization)-based model for the
optimal management of a small PV
(Photovoltaic)-pump hydro energy storage
in a rural dry area. Energy, 76, pp.168-174.
[10] Yu, Q., Wang, Y., Gao, J., Gao, S. and
Flemming, B., 2014. Turbidity maximum
formation in a well‐mixed macrotidal
estuary: The role of tidal pumping. Journal
of Geophysical Research: Oceans, 119(11),
pp.7705-7724.
[11] Zhang, J., Liu, J., Campana, P.E.,
Zhang, R., Yan, J. and Gao, X., 2014. Model
of evapotranspiration and groundwater level
based on photovoltaic water pumping
system. Applied energy, 136, pp.1132-1137.

[12] Zhu, J., Hu, K., Lu, X., Huang, X., Liu,
K. and Wu, X., 2015. A review of
geothermal energy resources, development,
and applications in China: Current status and
prospects. Energy, 93, pp.466-483. Chen, J.,
Ganigué, R., Liu, Y. and Yuan, Z., 2014.
Real-time multistep prediction of sewer flow
for online chemical dosing control. Journal
of Environmental Engineering, 140(11),
p.04014037.