Systems that need a Lift

PUMP TYPESSump

Clean Water Only

Effluent Multi stage

Single stage

Sewage Grinder

Pumping to Gravity Distribution When STA is at higher elevation than septic tank

Pump Sizing

TDH

Set by Location

Impacted by flow

GPM

15 - 45 gpm

Dose to Gravity

Do not pump downhill

Does not result in uniform distribution in laterals

Can discharge to either parallel or sequential

network.

Think about this before installing…..

Distribution Box and Tiered Trenches

Pressure Manifold Pressure DistributionDesigned to distribute effluent uniformly over infiltrative

surface of receiving component.

Pumping to Pressure

Distribution Pressure Distribution Uses a network of small diameter pipe [1”-2”] and

small orifices [1/8”-1/4”]

NSFC

The ‘Right’ Pump for

Pressure Distribution TDH

Set by

Elevation

Flow Rate – Pipe Diameter

Distribution

GPM

Set by

Number of orifices

[6- 10 sqft per orifice]

Orifice size

Operating pressure

System Curve

Pump Curve

System Curve

How Pump Works

Elevation Head

Pipe Friction

Manifold Loss

Where it Operates

Pump Efficiency

Pump & System Curves

0

20

40

60

80

100

120

5 10 15 20 25 30 35 40 45 50 55 60 65

gpm

tdh

0.5 hp Pump

1.0 hp Pump

System Curve at El 0

System Curve at El +5

Pressure Distribution Design considerations

May use flow-splitting devices to minimize pump size

Pump Vault

Pumping from the Source

The pump

Sizing

Location

Maximum Volume The floats

The Electrical

The controls

The Sump Venting

Outside: In the System

Pump Applications Media Filter

Pump Tank

What size tank?

Capacity Dose volume

PLUS

Storage

Or Two Pumps Replaces storage

Every Pump Should Be:

Accessible

Replaceable

Wired Properly

Elevated

Controlled

Accessible Access from surface

Under the manhole

Manhole to the surface

Quick disconnect

Not Fernco

Reachable

Within 20” of the surface

Control Panel

Line of Site

Nuisance

Replaceable

Removable

Pump

Floats

Ability to lift the pump

Reconnecting the pump

Electrician?

Reconnecting the controls

Pump Wiring

In & out of the Tank

Conduit [1”-2”]

Safe in the Sewage

environment,

EXCEPT FOR

SPLICES!!

Electrical tape is not

watertight

Electrical components

sealed and watertight?

Venting

Be careful

All electrical should be sealed

If necessary vent thru a filter for odors

Electrical

The right size wire

Pump size [hp]

Distance

Separate Circuits

Pump

Alarm

Wiring

Be careful of

the power

Hard conduit

around the tank

Pump should be:

Elevated off

bottom

Storage

Covered

with effluent

Protection

Pump Basin [Elevated]

Make sure the floats do not rest on the basin lip

Controlled Demand

Piggy back

Floats

Timed

Demand Dosing

Dose occurs when sufficient volume of effluent has

been collected.

Dosing frequency depends on how much wastewater

is being generated.

There is no control on how much effluent is being

dosed daily.

Demand

Dosing Two or Three

floats

On level sets the

volume

Check valve holds

effluent in the piping

Off level above the

pump

Water Level SensorsFloat

Pressure

Wet

The Floats [Controls] Activation angle

Voltage

Float Switches

Mercury Float Switch Mechanical Float Switch

Sensor Attachment

Sensor can be:

Tethered to float tree

Weighted tether from riser

Attached to bracket

on riser

Float Tree Dose Volume (DV)

Maximum~

Daily flow ÷ 4

600 ÷ 4= 150 gal

Minimum~

4 times piping volume*

Example:

3 trenches w/40’ of 1.5” pipe

3 x 40’ x 0.10 gal/ft

12 gal x 4 = 48 gals

* Some sources say 5X piping volume

Drawdown and Dose Volume

Drawdown (in) = Dose Volume

(gallons) ÷ GPI (gallons per inch)

of drawdown

Where:

GPI = Area of dosing tank or

chamber (in square ft) x 0.083 ft

x 7.5 gal/ft3

Note: 1” = ½ ft or 0.083 ft

Area = length X width (of dosing

chamber or dose tank)

Calculating Drawdown

Surface Area

Rectangle: 4’ x 7’ tank

L x W = Area

4’ x 7’ = 28 ft2

Circle: 4’ diameter

Radius is half of diameter 4 ÷

2 = 2’

Π x [radius]2= 3.14 x r x r

3.14 x 2 x 2 = 12.5 ft2

Top View

Length= 7’

Diameter = 4’

Radius = 2’

Width= 4’

Gallons Per Inch Area x 0.083’ x 7.5 gal/ft3

= gal/inch

28 ft2 x 0.083’ x 7.5

gal/ft3= 17.5 gal/in 12.5 ft2 x 0.083’ x 7.5

gal/ft3 = 7.8 gal/in

Plan View

Dose Volume (DV)

Drawdown (in) = Dose Vol. ÷ GPI

Dose volume ~ 100 gal

Drawdown = 100 gal ÷ 17.5 gal/in

5.7”

Nominal Pipe Size (in)

Water Content (per ft. pipe)

VolumeWeight (lbs.)

(cu. in) (gallons)

1/4 0.59 0.003 0.02

3/8 1.33 0.006 0.05

1/2 2.36 0.010 0.09

3/4 5.30 0.023 0.19

1 9.43 0.041 0.34

1 1/4 14.7 0.064 0.53

1 1/2 21.2 0.092 0.77

2 37.7 0.163 1.36

2 1/2 58.9 0.255 2.13

3 84.8 0.367 2.31

4 150.8 0.653 5.44

5 235.6 1.02 8.50

6 339.3 1.47 12.2

8 603.2 2-61 21.8

10 942.5 4.08 34.0

12 1357.2 5.88 49.0

15 2120.6 9.18 76.5

Typical Pipe Volume Table Without a Check Valve 100 gal Pumped Volume= PV

Must subtract the drain back

Drain back = Volume of pipe

Drain back = Volume/LF x LF of pipe

Ex: 60’ of 2 inch pipe

Drain back = 60 ft x 0.17 gal/ft = 10.2 gal

Dose Volume = PV – Drain back

DV = 100 gal – 10.2 gal = 89.8 gal

that reaches the STA

Floats

Pump Cover ~ Off

4”+ 14” + 2”= 20”

Dose~ On

5.7”

20”+5.7”= 25.7”

Alarm

3”

25.7”+3”= 28.7”

Float Switch or

Piggy back

Low cost

Controlled by

volume only

Easy wiring

Timers Timed Dosing

A timer controls the number of doses per day and the

dose volume.

Will allow only a certain amount of effluent to be

dosed daily.

Protects downstream components from overloading.

Useful for controlling surges or big-flow days.

Functions Off [Float]

Turns timer off

On Timer operates the

pump

Alarm Turns on the alarm

Peak Enabler Changes the dosing

frequency (PLC)

Alarm

Audible

Visual

Lateral Cleanouts

Single Pass Sand Filter With

Discharge Pump

Geo-FabricLoamy Sand or

Decorative Rock

Stone (2" Over Pipe)

Filter Sand (See Specifications)

Pea Gravel

30 MIL PVC Liner

Pump Basin Sand

Backfill

2" Sand

Leveling Layer

PVC Lateral w/

Orifice Shields

Flushing

ValveValve Box

Liner Support

(1/2" Plywood)

To Soil

Optional Lateral/Flushing

Valve Connections

6"

6"

2'

6"

Sweep 2 - 45°

Lateral End Clean-Out Types

Straight ends Threaded caps

Ball valves

Sweep 90 degree elbows (electrical sweeps are pressure rated)

2 - 45 degree elbows

Equipment Selection

Don’t let supplier select your equipment

Better to talk to manufacturer

DON’T change components specified in design

without consulting the designer; you are accepting

liability

Questions?

Low-Pressure Distribution

DrainfieldShallow Narrow Drainfield

Orifices in Laterals:

Lay out and number the laterals

Use a string line to mark pipe

Pay attention to orientation and spacing

Location of first/last orifice in each lateral may vary

Drilling Orifices

Use a new bit

Use the correct size

Keep the drill

vertical

Don’t “wallow” or it

will be too large

Orifice shape

affects flow

Pressure System Orifice Shields

Keep media away from orifice

Follow manufacturer recommendations

Spacing and size of delivery devices

Little to n

o s

lope

Level sites: orifice size and spacing is typically the

same in each lateral

Slo

pe

Spacing of delivery devices

Sloping sites: spacing may vary to maximize uniformity

CAUTION: if diameter varies, smaller orifices may clog

more quickly

Balancing Unlevel Distribution

Goal:

Splitting the flow equally

Level ~Easy

Problem

Separate Pieces

Typically equal

Separate pumps

Alternating

Splitter valves

Hydro Splitter

(ADV)Using Valves

Balancing the pressure

Flow Regulating Valves

Adding one increases friction loss

Globe valve is best but most expensive

Gate valve is better

Should NOT be a ball valve

Valve Boxes

Design Orifice spacing and sizing

Sprays to the same height

Lower laterals

Higher pressure

Smaller holes

Larger spacing

Questions?