pressure distribution systems -...

Website Version

Oct 2014

1

Pressure Distribution Systems

Roxanne Groover

Florida Onsite Wastewater Association

4

How does dosing effect

drainfield longevity?

• Designed to use entire drainfield each dose

• Alternately wet and dry conditions

• Biomat is partially consumed as oxygen is

drawn down behind wetting front

• Can accept many times more pounds of

BOD per sq ft of surface (Hargett, 1984)

5

Why use a pump?

• Required by 64E-6, Florida Administrative Code for “large” drainfields (over 1000 sq. ft total required area).

• To overcome a low plumbing stubout or elevation/distance challenges on a lot.

Code calls this “lift dosing”.

• To control peak loading stress (e.g., Church, Flea Market).

• Establishments with high strength wastes to spread the biological loading to enhance exposure to bacteria for quick removal.

6

Warning!!!

• Tank watertightness is a must !

– Exfiltration pollutes the groundwater.

– Infiltration burns up the pump and overloads

the drainfield.

• In some states, all mounded drainfields are

pressure dosed.

7

Conventional Gravity Distribution

• Creeping failure principle….

• Entire flow out the nearest and lowest holes.

• Locally clog the bottom beneath that hole.

• Begin to spread out laterally along the bottom

• Once entire bottom surface clogged, begins to

rely on using the sidewall.

8

Once we rely on sidewall, which

type of a gravity system is

superior, a bed or a trench?

9

Example Bed System

• Four bedroom home (400 gpd)

• Subsurface aggregate bed 12” deep 30 ft long

• Loamy Fine Sand (0.35 gpd/ft2)

• GIVEN: 40% pore space, ignore pipe, 1 cubic ft equals 7.5 gallons

• FIND: TOTAL STORAGE VOLUME IN THE DRAINFIELD

10

Example Bed System solution

• Area = Q (gpd) ÷LTAR (gpd/ft2)

• Area = 400 gpd ÷ 0.35 gpd/ft2 = 1143 ft2

• Volume = Area (ft2) x Depth (ft)

• Volume = 1143 ft2 x 1 ft thick = 1143 ft3

• Void volume = volume (ft3) x % pore space

• Void volume = 1143 ft3 x 0.40 = 457 ft3

• Total Storage Volume = VV(ft3) x 7.5 G/ft3

• Total Storage Volume (in gallons)

457ft3 x 7.5 gallons/ft3 = 3429 gallons

11

Bed System Safety factor against

surge overload

• If the above drainfield was dry, but all bottom

and sidewall surfaces were clogged, how

many days could it accept this home’s

effluent?

12


surge overload - solution

• Total Storage volume = 3429 gallons

• Daily Estimated Sewage flow = 400 gpd

• Safety Factor = 3429 gal/400 gpd = 8.6

days

13

Sidewall Safety factor against

Clogged bottom surface

• If the the bottom surface of the example bed

drainfield was completely clogged, how

many gallons of effluent would have to pass

through the sidewall per day per linear foot

of sidewall to keep this home’s effluent from

surfacing?

14


clogged bottom surface - solution

• Let bed width = 30 ft

• Bed length= 1143ft2/30 ft = 38 ft

• Bed perimeter = 30ft + 38ft + 30ft + 38ft= 136 linear ft

• Sidewall infiltration rate = 400 gpd/136 ft =2.94 gal/ linear ft/day

• At 12” deep drainfield=LTAR of 2.94 gallons

per sq ft per day

15

Example Trench System

• Four bedroom home (400 gpd).

• Subsurface aggregate 12”deep 36” wide.

• Loamy Fine Sand (0.65 gpd/ft2).

• GIVEN: 40% pore space, ignore pipe, 1

cubic ft equals 7.5 gallons.

• FIND: TOTAL STORAGE VOLUME IN THE

DRAINFIELD.

16

Example Trench System solution

• Area = Q (gpd) ÷LTAR (gpd/ft2)

• Area = 400 gpd ÷ 0.65 gpd/ft2 = 615 ft2

• Volume = Area (ft2) x Depth (ft)

• Volume = 615 ft2 x 1 ft thick = 615 ft3

• Void volume = volume (ft3) x % pore space

• Void volume = 615 ft3 x 0.40 = 246 ft3

• Total Storage Volume = VV(ft3) x 7.5 G/ft3

• Total Storage Volume (in gallons)

246 ft3 x 7.5 gallons/ft3 = 1846 gallons

17

Trench System Safety factor

against surge overload

• If the above drainfield was dry, but all bottom

and sidewall surfaces were clogged, how

many days could it accept this home’s

effluent?

18

Trench System Safety factor against

surge overload - solution

• Total Storage volume = 1846 gallons

• Daily Estimated Sewage flow = 400 gpd

• Safety Factor = 1846 g/400 gpd = 4.6 days

19

Sidewall Safety factor against

Clogged bottom surface

• If the the bottom surface of the example trench

drainfield was completely clogged, how many

gallons of effluent would have to pass through the

sidewall per day per linear foot of sidewall to keep

this home’s effluent from surfacing? Assume three

trenches. Include the ends of the trenches in the

calculation

20

Trench System Safety factor

against clogged bottom surface -

solution

• Total drainfield area= 615 ft2

• Total drainfield length = 615 ft2/3ft = 205 ft

• Sidewalls = 205 ft x 2 = 410 linear ft

• Endwalls = 6 ends x 3 ft = 18 linear ft

• Total perimeter = 410 ft + 18 ft = 428 linear ft

• Sidewall infiltration rate = 400 gpd/428 linear ft =0.93 gal/

linear ft/day

• At 12” depth=LTAR of 0.93 gallons per sq ft per day

21

Comparison Data

• BED SYSTEM

� 2.94 gal/linear ft

� 8.57 days storage

• TRENCH SYSTEM

� 0.93 gal/linear ft

� 4.62 days storage

22

What pumpers need to know

about dosing systems

• Do not leave dosing tanks bone dry (float)

• Will suck in sediment first time used (pump mounted on blocks helps prevent this)

• Turn off, pump chamber dry and refill to top of pump casing at least

• If pump is exposed corrosive gases can attack the metal

• Make sure low level cutoff is above casing of pump

• Effluent surrounding pump keeps the pump cool

23

“By placing 100% of the pump

housing under effluent 100% of

the time - you will double the

effective pump life”

Chuck Schwabe

Zoeller Pump Company

24

What Installers need to

know about dosing systems

• Not as simple as picking up a sump pump at the local discount hardware store

• Horsepower is not the key

• Determine GPM and Total Dynamic Head, then compare to published pump curves

• Small design improvements have big payoffs:

--put check valve in vertical leg of discharge pipe

--drill a drain hole in bottom of each line of drainfield pipe furthest from the pump

25

What Installers need to know

about dosing systems (pg 2 of 2)• If tank is not watertight, during high water conditions you are

pumping and treating the effluent plus any rainwater that finds its way into the system

• Check pipe penetrations, risers & lids for complete watertight seal

• Including gate or ball valves at key points gives flexibility in dealing with problems

• More small design improvements have big payoffs: --set pump beneath four blocks , not just one--use true union connectors so can pull pump easily--use float tree, don’t strap floats to pump discharge pipe

Let’s Talk Design

26

27

Considerations

• Many design ‘preferences’ involved

• Two competent designers can come up with

very different solutions

• Sometimes external forces push solution,

e.g.

Site constraints

Availability or cost of materials

• Owners suggestions

28

Steps in Sizing Low Pressure

Distribution Networks

• Determine estimated sewage flow

(64E-6, Table I)

• Determine soil textural classification

and ESHWT (field, site/soil evaluation)

– Use to determine maximum sewage

loading rate(s) in trench and bed

configurations (64E-6, Table III & mound)

29

Selecting Pipe Networks:

• Header line sizing

• Lateral line sizing

• Hole diameters and hole spacing-very important

• Transmission line sizing

• Total dynamic head=static head + frictional head + working head

• Pump selection

30

Supplemental Handouts

1. Scouring gal/min for various diameters

2. Discharge rates for various hole diameters

3. Friction loss in various pipe diameters

4. Friction loss for fittings worksheet example

5. Volume per foot for various pipe diameters

6. Dosing system decision tree

7. Tank sizes and LTAR excerpts from rule

8. Pump curve

31

Scouring Velocity

• If flow inside pipe gets too slow

suspended materials in pipe get left

behind

• Called ‘stranding solids’

• Will eventually clog network

• If flow at 2 ft / sec or higher will eject

suspended solids with the fluids

32

Minimum gpm to achieve scouring velocity (2 ft/sec)

for common pipe diameters

equation: 4.896 (d2) = GPM

Pipe Diameter (in.)

Nominal (actual)

Minimum GPM

Actual (use)

0.50 (.622) 1.89 (2)

0.75 (.824) 3.32 (4)

1.00 (1.049) 5.39 (6)

1.25 (1.380) 9.32 (10)

1.5 (1.610) 12.69 (13)

2.0 (2.067) 20.92 (21)

2.5 (2.469) 29.84 (30)

3.0 (3.068) 46.08 (46)

4.0 (4.026) 79.35 (80)

33

Discharge rates for various sized

holes at various pressures (in gpm)Operating

head

3/32 1/8 5/32 3/16 7/32 1/4 5/16 3/8 7/16

1 ft(0.43 psi)

0.10 0.18 0.29 0.42 0.56 0.74 1.15 1.66 2.26

2 ft (0.87 psi)

0.15 0.26 0.41 0.59 0.80 1.05 1.63 2.34 3.19

3 ft (1.30 psi)

0.18 0.32 0.50 0.72 0.98 1.28 1.99 2.87 3.91

4 ft (1.73 psi)

0.21 0.37 0.58 0.83 1.13 1.48 2.30 3.31 4.51

5 ft (2.17 psi)

0.23 0.41 0.64 0.94 1.26 1.65 2.57 3.71 5.04

Flow

gallons Pipe Diameter (inches)

per nominal 0.50 0.75 1.00 1.25 1.50 2.00 2.50 3.00 4.00

minute actual 0.622 0.824 1.049 1.380 1.61 2.067 2.47 3.068 4.026

1 0.98 0.25 0.08 0.02 0.01

2 3.54 0.90 0.28 0.07 0.03 0.01

3 7.51 1.91 0.59 0.16 0.07 0.02 0.01

4 12.79 3.26 1.01 0.26 0.13 0.04 0.02 0.01

5 19.34 4.92 1.52 0.40 0.19 0.06 0.02 0.01

6 6.90 2.13 0.56 0.27 0.08 0.03 0.01

7 9.18 2.84 0.75 0.35 0.10 0.04 0.02

8 11.75 3.63 0.96 0.45 0.13 0.06 0.02 0.01

9 14.62 4.52 1.19 0.56 0.17 0.07 0.02 0.01

10 17.77 5.49 1.45 0.68 0.20 0.09 0.03 0.01

11 21.20 6.55 1.72 0.81 0.24 0.10 0.04 0.01

12 24.90 7.69 2.03 0.96 0.28 0.12 0.04 0.01

13 8.92 2.35 1.11 0.33 0.14 0.05 0.01

14 10.24 2.70 1.27 0.38 0.16 0.06 0.01

15 11.63 3.06 1.45 0.43 0.18 0.06 0.02

16 13.11 3.45 1.63 0.48 0.20 0.07 0.02

17 14.66 3.86 1.82 0.54 0.23 0.08 0.02

18 16.30 4.29 2.03 0.60 0.25 0.09 0.02

19 18.02 4.74 2.24 0.66 0.28 0.10 0.03

20 19.81 5.22 2.46 0.73 0.31 0.11 0.03

25 29.95 7.89 3.73 1.10 0.47 0.16 0.04

30 11.06 5.22 1.55 0.65 0.23 0.06

35 14.71 6.95 2.06 0.87 0.30 0.08

40 18.84 8.90 2.64 1.11 0.39 0.10

45 23.43 11.07 3.28 1.38 0.48 0.13

50 28.48 13.45 3.99 1.68 0.58 0.16

55 33.97 16.05 4.76 2.00 0.70 0.19

60 18.85 5.59 2.35 0.82 0.22

65 21.87 6.48 2.73 0.95 0.25

70 25.08 7.44 3.13 1.09 0.29

75 28.50 8.45 3.56 1.24 0.33

80 32.12 9.52 4.01 1.39 0.37

85 10.65 4.49 1.56 0.42

90 11.84 4.99 1.73 0.46

95 13.09 5.51 1.92 0.51

100 14.40 6.06 2.11 0.56

110 17.18 7.23 2.51 0.67

120 20.18 8.50 2.95 0.79

130 23.40 9.86 3.43 0.91

140 11.31 3.93 1.05

150 12.85 4.47 1.19

160 14.48 5.03 1.34

170 16.20 5.63 1.50

180 18.01 6.26 1.67

190 19.91 6.92 1.84

200 21.89 7.61 2.03

225 9.46 2.52

250 11.50 3.07

300 16.12 4.30

Friction Loss in Schedule 40 Plastic Pipe, C = 150

(Feet / 100 Feet) f/n:head loss in pipe-01.xls

Excessive

Head Loss

Low

Velocity

36

Volume of effluent per foot of pipe length (in gallons)

equation: .0408 (d2) = gallons

Pipe Diameter (in.)

Nominal (actual)

Volume per foot

(gallons)

0.50 (.622) .016

0.75 (.824) .028

1.00 (1.049) .045

1.25 (1.380) .078

1.5 (1.610) .106

2.0 (2.067) .174

2.5 (2.469) .249

3.0 (3.068) .384

4.0 (4.026) .661

Dosing Tree

37

Table II - Septic/pump tank

capacityAverage Sewage Flow (gpd)

Septic Tank effective capacity (gallons)

Residential Pump Tank effective capacity (gallons)

Commercial Pump Tank effective capacity (gallons)

0-200 900 150 225

201-300 900 225 375

301-400 1050 300 450

401-500 1200 375 600

501-600 1350 450 600

601-700 1500 525 750

701-800 1650 600 900

801-1000 1900 750 1050

1001-1250 2200 900 1200

1251-1750 2700 1350 1900

1751-2500 3200 1650 2700

2501-3000 3700 1900 3000

3001-3500 4300 2200 3000

3501-4000 4800 2700 3000

4001-4500 5300 2700 3000

4501-5000 5800 3000 3000

39

PUMP must reach capacity

against Total Dynamic Head

• Total Dynamic Head =

– Static Head, plus

– Friction Head, plus

– Operating Head

• TDH = SH +FH+OH

40

Static Head

• Also known as elevation head.

• The vertical distance from off point of

pump (or lowest water level in pump

chamber) to the point of discharge,

usually the header pipe.

• NOTE: if lines are not level, choose the

highest point (why?)

41

Friction Head

• Resistance to flow of fluid against side walls

of pipes and fittings.

• Friction Head a function of:

Pipe diameter (smaller, more friction)

Capacity (more flow, more friction)

Configuration (+fittings, more friction)

Pipe materials (PVC, Steel, Cast Iron)

Age (older more friction) why?

42

Friction Head

• Represented as equivalent length of pipe,

As if you could remove the fitting and

replace it with a length of straight pipe with

the same friction loss

• Table A in SSPMA handout

Frictional Loss Worksheet

44

720 Gallon per day bed system

Fitting Size Qty X Equivalent = Total Total

Length per fitting per location

LOCATION: (ft) (ft)

pump well: pipe 2" 5.00

____ GPM check valve 2" 1.00

union 2" 1.00

gate valve 2" 1.00

90 ell 2" 1.00

transmission line pipe 2" 150.00

_____ GPM 45 ell 2" 1.00

=======

header: pipe 3" 35.00

____ GPM 90 ell 3" 2.00

Tee's 3" 6.00 =======

lateral pipe 1.25" 50.00

use only 1 line =======

____ GPM

45

Operating Head

• Pressure desired at the holes (orifices)

• How high the water rises in a standpipe at

the distal lateral hole location.

• 1-3 ft is reasonable to keep holes clear

• Placing the furthest hole pointing down

allows flow to drain to end of lines when

pump kicks off, also drains off solids

46

With TDH & Pump Capacity

• Locate point on pump curve

• Pumps vary + 10% from published values

• Use a pump curve slightly above and to the

right of point plotted

Pump Curve

47

48

Select Central or End manifold

• Central manifold - discharge laterals arranged off both sides (letter ‘H’)

• End manifold - looks like a typical trench system (letter ‘E’)

• With the same system size, central manifolds have half the length of discharge laterals, but twice the number of laterals

49

1

2

3

4

50

1

2

3

4

5

51

Steps in sizing low pressure

distribution networks (cont.)• Determine the number of doses per rule.

– Moderately limited soil = maximum of 2.

– Slightly limited soil = maximum of 6.

• Calculate volume per dose by 64E-6.

• Calculate volume required to fill the laterals one time

• Calculate number of pipe fills per dose. Rule requires minimum of 4.

52

Steps in sizing low pressure

distribution networks (cont.)

• Finally, review your design

• EPA tables assume 10 fills/cycle 64E-6 requires 4 fill/cycle

• 64E-6 – slightly limited soils maximum of 6 doses per 24 hours, moderately limited soils maximum of 2 doses per 24 hour

• PE can specify more frequent doses, but not less than one fill per cycle

• Determine pump chamber size per 64E-6 Table II

Let’s Try A Design

•Steps will be listed in following slides

•Examples in class/test could be:– Bed or trench

– Side or end manifold

– Residential or commercial

– Various soils

– Various GPD

53

54

Website Example

• A (varies) gallon per day (bed/trench) Onsite Sewage Treatment and Disposal System serves a (residential/commercial)waste establishment. The soil is a (varies). The system site has an estimated seasonal high water table of (varies) inches below grade at the drainfield location.

• GIVEN:

• (varies) gpd system

• (varies) configuration

• (varies) soil

Website Example

• What is the proper size of the septic tank?

– From 64E-6 Table II

• What is the proper size of the pump tank?

– From 64E-6 Table II

• Residential or commercial

55

Table II - Septic/pump tank

capacityAverage Sewage Flow (gpd)

Septic Tank effective capacity (gallons)

Residential Pump Tank effective capacity (gallons)

Commercial Pump Tank effective capacity (gallons)

0-200 900 150 225

201-300 900 225 375

301-400 1050 300 450

401-500 1200 375 600

501-600 1350 450 600

601-700 1500 525 750

701-800 1650 600 900

801-1000 1900 750 1050

1001-1250 2200 900 1200

1251-1750 2700 1350 1900

1751-2500 3200 1650 2700

2501-3000 3700 1900 3000

3001-3500 4300 2200 3000

3501-4000 4800 2700 3000

4001-4500 5300 2700 3000

4501-5000 5800 3000 3000

Website Example

• What is the long term acceptance rate

(LTAR) of the effluent passing through the

infiltrative bottom surface of drainfield?

– GIVEN:

• (varies) soil

• From 64E-6 – soil chart in example is for mounds please be aware that is not the only chart available

and be sure to use correct one depending on type of

system (subsurface, filled, or mound)

57

Website Example

• What is the total drainfield area?

– Estimated Sewage Flow/LTAR

– From 64E-6

59

Website Trench Example(Different from beds)

• Choose a desired width & # of trenches

– This is typically chosen by designer

– In class instructor/class will choose

• What is trench length?

– Area of drainfield/trench width/# of trenches

– 1250/3/8 = 52 ft - #5

60

Website Example

• Choose a hole diameter and spacing

• Choose a distal operating head

• How many holes are there in each lateral?

– Trench Length/hole spacing

61

Website Example

• What is the discharge rate through each

7/32” hole?

– Use chart

62

63

Discharge rates for various sized

holes at various pressures (in gpm)

Operating

head

3/32 1/8 5/32 3/16 7/32 1/4 5/16 3/8 7/16

1 ft(0.43 psi)

0.10

0.18 0.29 0.42 0.56 0.74 1.15 1.66 2.26

2 ft (0.87 psi)

0.15

0.26 0.41 0.59 0.80 1.05 1.63 2.34 3.19

3 ft (1.30 psi)

0.18

0.32 0.50 0.72 0.98 1.28 1.99 2.87 3.91

4 ft (1.73 psi)

0.21

0.37 0.58 0.83 1.13 1.48 2.30 3.31 4.51

5 ft (2.17 psi)

0.23

0.41 0.64 0.94 1.26 1.65 2.57 3.71 5.04

Website Example

• What is the discharge through each lateral?

– # of holes x discharge rate per hole

64

Website Example

• What is the lateral diameter:

– From chart

• What is the flow per system?

– Flow per lateral x total number of trenches

65

Flow


per nominal 0.50 0.75 1.00 1.25 1.50 2.00 2.50 3.00 4.00

minute actual 0.622 0.824 1.049 1.380 1.61 2.067 2.47 3.068 4.026

1 0.98 0.25 0.08 0.02 0.01

2 3.54 0.90 0.28 0.07 0.03 0.01

3 7.51 1.91 0.59 0.16 0.07 0.02 0.01

4 12.79 3.26 1.01 0.26 0.13 0.04 0.02 0.01

5 19.34 4.92 1.52 0.40 0.19 0.06 0.02 0.01

6 6.90 2.13 0.56 0.27 0.08 0.03 0.01

7 9.18 2.84 0.75 0.35 0.10 0.04 0.02

8 11.75 3.63 0.96 0.45 0.13 0.06 0.02 0.01

9 14.62 4.52 1.19 0.56 0.17 0.07 0.02 0.01

10 17.77 5.49 1.45 0.68 0.20 0.09 0.03 0.01

11 21.20 6.55 1.72 0.81 0.24 0.10 0.04 0.01

12 24.90 7.69 2.03 0.96 0.28 0.12 0.04 0.01

13 8.92 2.35 1.11 0.33 0.14 0.05 0.01

14 10.24 2.70 1.27 0.38 0.16 0.06 0.01

15 11.63 3.06 1.45 0.43 0.18 0.06 0.02

16 13.11 3.45 1.63 0.48 0.20 0.07 0.02

17 14.66 3.86 1.82 0.54 0.23 0.08 0.02

18 16.30 4.29 2.03 0.60 0.25 0.09 0.02

19 18.02 4.74 2.24 0.66 0.28 0.10 0.03

20 19.81 5.22 2.46 0.73 0.31 0.11 0.03

25 29.95 7.89 3.73 1.10 0.47 0.16 0.04

30 11.06 5.22 1.55 0.65 0.23 0.06

35 14.71 6.95 2.06 0.87 0.30 0.08

40 18.84 8.90 2.64 1.11 0.39 0.10

45 23.43 11.07 3.28 1.38 0.48 0.13

50 28.48 13.45 3.99 1.68 0.58 0.16

55 33.97 16.05 4.76 2.00 0.70 0.19

60 18.85 5.59 2.35 0.82 0.22

65 21.87 6.48 2.73 0.95 0.25

70 25.08 7.44 3.13 1.09 0.29

75 28.50 8.45 3.56 1.24 0.33

80 32.12 9.52 4.01 1.39 0.37

85 10.65 4.49 1.56 0.42

90 11.84 4.99 1.73 0.46

95 13.09 5.51 1.92 0.51

100 14.40 6.06 2.11 0.56

110 17.18 7.23 2.51 0.67

120 20.18 8.50 2.95 0.79

130 23.40 9.86 3.43 0.91

Friction Loss in Schedule 40 Plastic Pipe, C = 150

(Feet / 100 Feet) f/n:head loss in pipe-01.xls

Excessive

Head Loss

Low

Velocity

Website Example

• End Connection or Center Connection?

• What is the manifold diameter?

– From chart

67

Flow


per nominal 0.50 0.75 1.00 1.25 1.50 2.00 2.50 3.00 4.00

minute actual 0.622 0.824 1.049 1.380 1.61 2.067 2.47 3.068 4.026

1 0.98 0.25 0.08 0.02 0.01

2 3.54 0.90 0.28 0.07 0.03 0.01

3 7.51 1.91 0.59 0.16 0.07 0.02 0.01

4 12.79 3.26 1.01 0.26 0.13 0.04 0.02 0.01

5 19.34 4.92 1.52 0.40 0.19 0.06 0.02 0.01

6 6.90 2.13 0.56 0.27 0.08 0.03 0.01

7 9.18 2.84 0.75 0.35 0.10 0.04 0.02

8 11.75 3.63 0.96 0.45 0.13 0.06 0.02 0.01

9 14.62 4.52 1.19 0.56 0.17 0.07 0.02 0.01

10 17.77 5.49 1.45 0.68 0.20 0.09 0.03 0.01

11 21.20 6.55 1.72 0.81 0.24 0.10 0.04 0.01

12 24.90 7.69 2.03 0.96 0.28 0.12 0.04 0.01

13 8.92 2.35 1.11 0.33 0.14 0.05 0.01

14 10.24 2.70 1.27 0.38 0.16 0.06 0.01

15 11.63 3.06 1.45 0.43 0.18 0.06 0.02

16 13.11 3.45 1.63 0.48 0.20 0.07 0.02

17 14.66 3.86 1.82 0.54 0.23 0.08 0.02

18 16.30 4.29 2.03 0.60 0.25 0.09 0.02

19 18.02 4.74 2.24 0.66 0.28 0.10 0.03

20 19.81 5.22 2.46 0.73 0.31 0.11 0.03

25 29.95 7.89 3.73 1.10 0.47 0.16 0.04

30 11.06 5.22 1.55 0.65 0.23 0.06

35 14.71 6.95 2.06 0.87 0.30 0.08

40 18.84 8.90 2.64 1.11 0.39 0.10

45 23.43 11.07 3.28 1.38 0.48 0.13

50 28.48 13.45 3.99 1.68 0.58 0.16

55 33.97 16.05 4.76 2.00 0.70 0.19

60 18.85 5.59 2.35 0.82 0.22

65 21.87 6.48 2.73 0.95 0.25

70 25.08 7.44 3.13 1.09 0.29

75 28.50 8.45 3.56 1.24 0.33

80 32.12 9.52 4.01 1.39 0.37

85 10.65 4.49 1.56 0.42

90 11.84 4.99 1.73 0.46

95 13.09 5.51 1.92 0.51

100 14.40 6.06 2.11 0.56

110 17.18 7.23 2.51 0.67

120 20.18 8.50 2.95 0.79

Friction Loss in Schedule 40 Plastic Pipe, C = 150(Feet / 100 Feet) f/n:head loss in pipe-

ExcessiveHead Loss

Low

Frictional Loss Calculation

69

Total Dynamic Head (TDH)=

Static Head + Frictional Head + Operating Head

Website Example

• Pump Selection

– Static Head

– The elevation from the discharge port at the

pump to the drainfield (from site plan notes)

70

Website Example

• Pump Selection

– Frictional Head

• Use chart to determine frictional losses

71

73

??? Gallon per day ?? system

Fitting Size Qty X Equivalent = Total

Length per fitting

LOCATION: (ft)

pump well: pipe

?? GPM check valve

union

gate valve

90 ell

transmission line pipe

?? GPM 45 ell

=======

header: pipe

?? GPM 90 ell

Tee's =======

lateral pipe

?? GPM =======

Website Example

• Pump Selection

– Operational Head

– GIVEN:

• from initial design

74

Website Example

• Pump Selection

– Total Dynamic Head (TDH)

• Static Head + Frictional Head + Operating Head

• Pump Selection

– ?? GPM @ ?? ft of head - #16

75

Website Example

• Check number of fills

– What is the volume per linear foot of lateral line

(from table)?

76

77

Volume of effluent per foot of pipe length (in gallons)

equation: .0408 (d2) = gallons

Pipe Diameter (in.)

Nominal (actual)

Volume per foot

(gallons)

0.50 (.622) .016

0.75 (.824) .028

1.00 (1.049) .045

1.25 (1.380) .078

1.5 (1.610) .106

2.0 (2.067) .174

2.5 (2.469) .249

3.0 (3.068) .384

4.0 (4.026) .661

Website Example• Total volume

– volume per linear foot * # of laterals * length of

lateral

• There will be ? dose cycles per day

– Use 64E-6 to help w/# of dose cycles

• What is the volume per dose?

– Flow/# of doses

78

Website Example

• How many line fills will there be?

– Dose Volume/Total Lateral Volume

• Does this meet code requirements?

– Must be at least 4 fills according to 64E-6

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