Physical and Financial Performance of Pit Emptying Technologies

Jamie Radford Chloe Underdown, Stephanie Willis, Cameron Law, Jonathan Choksey,

Richard Fenner, Steven Sugden, Saurya Pal, Samrat Gupta,

Sampath Gopalan, George Drummond

Mott MacDonald

1. How strong is the sludge? Strength testing

2. How well do pumps perform? Pump testing

3. How does the business work? Financial

model

How much profit can be made emptying pits?

1. How strong is the sludge?

South 24 Parganas

Patna

Muzaffarpur 0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

0 1000 2000 3000

Dis

pla

cem

ent

(m)

Strength (Pa)

S24P, W Bengal, India – Pit 07

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

0 1000 2000 3000

Dis

pla

cem

ent

(m)

Strength (Pa) Patna, Bihar, India – Pit 35

2. How well do pumps perform?

Freeze-frame a still of the G3 video? Or G2 photo?

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0 100 200 300 400 500 600

Ave

rage

flo

w r

ate

(ℓ/s

)

Average sludge strength (Pa)

Pump testing results

Gulper 1

Gulper 2

Diaphragm

3. How does the business work?

Profit

= + <

Fee Fixed fee

Variable fee

Total Cost

Labour cost

Transportcost

Disposal cost

Hidden cost = + + +

=

-

Willing to pay limit

How much profit can I make emptying pits?

-$5

$-

$5

$10

$15

0,0

0,5

1,0

1,5

2,0

All areas,India

West Bengal Muzaffarpur Patna Kampala,Uganda

Pro

fit

pe

r p

it

Dep

th o

f sl

ud

ge (

m)

0 - 110Pa 110 - 180Pa 180 - 280Pa 280 - 430Pa

430 - 590Pa 590+ Pa Gulper 1 Gulper 2

Profit breakdown by pit

-$10

$0

$10

$20

0,0

1,0

2,0

3,0

4,0

Pro

fit

pe

r p

it

Tota

l dep

th (

m)

Patna, Bihar Muzaffarpur, Bihar S24 Parganas, W Bengal

-$40

-$20

$0

$20

$40

0,0

1,0

2,0

3,0

Pro

fit

pe

r p

it

Tota

l dep

th (

m)

590+ Pa

430 - 590Pa

280 - 430Pa

180 - 280Pa

110 - 180Pa

0 - 110Pa

Gulper 1

Gulper 2

Kampala, Uganda

How can I increase my profit?

Freeboard Emptiable Volume WTP Depth Strength

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Limitations of Gulper 2

India WB Patna Muzaf. Kampala

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Limitations of Gulper 1

India WB Patna Muzaf. Kampala

Which pump should I use?

0 100 200 300 400 500 600 700

0.5

1.0

1.5

2.0

2.5

3.0

Gulper 2Gulper 1

0 100 200 300 400 500 600 700

0.5

1.0

1.5

2.0

2.5

3.0

Gulper 1

Gulper 2

Patna/Muzaffarpur, India Kampala, Uganda

Dep

th o

f sl

ud

ge (

m)

Sludge strength (Pa)

Dep

th o

f sl

ud

ge (

m)

Sludge strength (Pa) 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Sludge strength (Pa)

Conclusion

• Testing sludge strength and pump performance can show how to increase profit for pit emptying

Next steps

• Test more pits – link to treatment and planning

• Test more pumps – mechanised, tankers

• Include more business model options

• Web tool to inform pump selection

Thank you!

Jamie Radford (@RadfordJT) Chloe Underdown, Stephanie Willis, Cameron Law, Jonathan Choksey,

Richard Fenner, Steven Sugden, Saurya Pal, Samrat Gupta,

Sampath Gopalan, George Drummond

Mott MacDonald

2. How well do pumps perform?

0 100 200 300 400 500 600

Ave

rage

Flo

w R

ate

(in

clu

din

g b

lock

ages

)

Shear Strength (Pa)

Impact of debris on Gulper I performance.

No debris

Debris

-25%

-40%

-100%

3. How does the business work?

Total Cost

Labour cost

Transportcost

Disposal cost

Hidden cost = + + +

Time to: - Travel - Negotiate - Set up - Empty - Blockages - Transport - Dispose x Hourly wages

Vehicle (hire) +

Fuel cost

Flat charge +

Fee per volume

Depreciation +

Maintenance +

Interest