Table 15.42.030(E)
Minimum Horizontal Setback Distances for OWTS (feet)
| ||||
---|---|---|---|---|
Site Feature
|
Building Sewer
|
Septic Tank
|
Dispersal Trench or Bed
|
Seepage Pit
|
Buildings or structures1
|
2
|
5
|
8
|
8
|
Property line
|
Clear2
|
5
|
5
|
8
|
Water supply wells
|
|
|
|
|
Domestic
|
503
|
150
|
150
|
150
|
Public
|
503
|
150
|
1504
|
2004
|
Springs
|
-
|
50
|
100
|
100
|
Streams
|
|
|
|
|
General (from top of bank)
|
50
|
100
|
100
|
150
|
Between 1,200'—2,500' of a public water intake5
|
-
|
-
|
200
|
200
|
Within 1,200' of a public water system intake5
|
-
|
-
|
400
|
400
|
Reservoirs
|
|
|
|
|
General
|
50
|
100
|
200
|
200
|
Within 1,200' of a public water supply intake5
|
-
|
-
|
400
|
400
|
Ocean waters (from mean high tide line)6
|
-
|
50
|
100
|
100
|
Storm drainage pipe7
|
|
5
|
50
|
50
|
Cut bank or embankment
|
-
|
10
|
4 x h8
|
4 x h8
|
Unstable land mass9
|
|
100
|
100
|
100
|
Trees
|
-
|
10
|
-
|
10
|
Seepage pit
|
-
|
5
|
5
|
12
|
Dispersal trench or bed
|
-
|
5
|
4
|
5
|
Distribution box
|
-
|
-
|
5
|
5
|
Onsite domestic service line
|
110
|
5
|
5
|
5
|
Pressure public water main
|
1011
|
10
|
10
|
10
|
Notes:
| |
---|---|
1
|
Including porches and steps, whether covered or uncovered, breezeways,
roofed porte cocheres, roofed patios, carports, covered walks, covered
driveways, and similar structures and appurtenances.
|
2
|
See California Plumbing Code, Section 321.3.
|
3
|
Drainage piping shall clear domestic water supply wells by not
less than 50 feet. This distance shall be permitted to be reduced
to not less than 25 feet where the drainage piping is constructed
of materials approved for use within a building.
|
4
|
200 feet for trench or seepage pit 10 feet deep; 2-yr microbial
travel study required for seepage pit >20′ deep within 600
feet of public water well, per Statewide OWTS Policy Section 9.4.10.3.
|
5
|
For areas tributary to and upstream of water supply intake;
setback distance measured from high water mark. Exceptions allowed
per Statewide OWTS Policy, as follows: (a) for replacement OWTS, comply
to the maximum extent practicable and incorporate supplemental treatment
unless the administrative authority finds no impact or significant
threat to water source; (b) for new OWTS on pre-existing lot of record
(pre-May 13, 2013), comply to maximum extent practicable and incorporate
supplemental treatment for pathogens per Sections 10.8 and 10.10 of
Statewide OWTS Policy as detailed in the Malibu OWTS Manual.
|
6
|
Systems that provide supplemental (secondary or tertiary) effluent
treatment prior to discharge to the subsurface effluent dispersal
systems are not required to meet these minimum horizontal setback
requirements provided that no parts of the OWTS are, at any time,
submerged or exposed to direct contact with these surface water bodies.
In the case of beachfront developments and redevelopments, the OWTS
shall, to the maximum extent feasible, be located at the farthest
point from the ocean on a parcel to avoid the construction of protective
structures such as sea walls and shoreline protection devices.
|
7
|
Where publicly owned storm drainage pipes run across a property
rendering it impossible to meet these minimum horizontal setback requirements,
the effluent dispersal system is allowed to be located within 50 feet
of the pipes provided that these pipes are positioned vertically higher
than the bottom of the effluent dispersal system or the applicant
demonstrates that the pipes are sealed so that there is no possibility
for shallow groundwater to infiltrate the storm drain.
|
8
|
"h" equals the height of cut or embankment, in feet. Where a
California certified engineering geologist and/or registered geotechnical
engineer finds and states in writing that the stability of the fill
or cut bank will not be compromised by a shorter horizontal separation
and that a shorter horizontal separation will not result in sewage
effluent daylighting, a shorter horizontal setback for the effluent
dispersal system can be used per the said geologist's recommendation.
|
9
|
Setback distance may be reduced in accordance with recommendations
provided in a geotechnical report prepared by a civil engineer or
professional geologist and addressed in the OWTS design report and
accompanying geotechnical report.
|
10
|
See California Plumbing Code, Section 720.0.
|
11
|
For parallel construction; for crossings, approval by the Health
Department shall be required.
|
Table 15.42.050(B)-1
Wastewater Design Flows for OWTS Treatment Units Serving Single-Family
Residences and Second Units
| |
---|---|
No. of Bedrooms
|
Design Flow (gal/day)
|
1 (Master bedroom)
|
300
|
2
|
450
|
3
|
600
|
4
|
750
|
5
|
900
|
6
|
1,050
|
>6
|
+ 150 per bedroom
|
Table 15.42.050(B)-2
Wastewater Design Flows for OWTS Treatment Units Serving Multiple
Dwelling Units
| |
---|---|
No. of Dwelling Units
(1 bedroom each)*
|
Design Flow (gal/day)
|
2
|
600
|
3
|
900
|
4
|
1,200
|
5
|
1,500
|
6
|
1,800
|
7
|
2,100
|
8
|
2,400
|
9
|
2,700
|
10
|
3,000
|
>10
|
+300 per unit
|
Notes:
| |
---|---|
*
|
Extra bedrooms add 150 gallons each.
|
Table 15.42.050(B)-3
Estimated Sewage/Waste Flow Rates
| |
---|---|
Type of Occupancy
|
Design Flow (gal/day)
|
Airports
|
|
-Per employee
|
15
|
-Per passenger
|
5
|
Auto washers
|
Per equipment mfg.
|
Bowling alleys, snack bar only (per lane)
|
75
|
Camps (per person)
|
|
-With central comfort station
|
35
|
-With flush toilets, no showers
|
25
|
-Day camps, no meals served
|
15
|
-Summer and seasonal
|
50
|
Churches, sanctuary, religious halls (per seat)
|
|
-without kitchen
|
5
|
-with kitchen waste
|
7
|
Dance halls (per person)
|
5
|
Day care (per patron, employee)
|
15
|
Factories and industrial buildings (per employee)
|
|
-no showers
|
25
|
-with showers
|
35
|
-cafeteria, add
|
5
|
Hospitals
|
|
-per bed
|
250
|
-kitchen waste only (per bed)
|
35
|
-laundry waste only (per bed)
|
5
|
Hotels, no kitchen waste (per bed x 2)
|
60
|
Institutions (per person)
|
|
-resident
|
75
|
-nursing home
|
125
|
-rest home
|
125
|
Laundries, self-service
|
|
-minimum 10 hours per day (per wash cycle)
|
50
|
-commercial
|
Per manufacturer
|
Motel (per bed space)
|
|
-no kitchen
|
50
|
-with kitchen
|
60
|
Offices (per employee)
|
20
|
Parks
|
|
-mobile homes (per space)
|
250
|
-picnic parks, toilets only (per parking space)
|
20
|
-Recreational vehicles (per space)
|
|
• without water hook-up
|
75
|
• with water and sewer hook-up
|
100
|
Restaurants – cafeterias
|
|
-per seat
|
50*
|
-per employee
|
20
|
-toilet (per customer)
|
7
|
-kitchen waste (per meal
|
6
|
-add for cocktail lounge (per customer)
|
2
|
-kitchen waste – disposable service (per meal)
|
2
|
Schools
|
|
-staff and office (per person)
|
20
|
-elementary students (per student)
|
15
|
-intermediate and high (per student)
|
20
|
• with gym and showers
|
5
|
• with cafeteria, add
|
3
|
-boarding, total waste (per person)
|
100
|
Service station, toilets
|
3
|
-for 1st bay
|
1,000
|
-add for each additional bay
|
500
|
Stores
|
|
-per employee
|
20
|
-public restrooms, add per 10 ft2 of floor space
|
1
|
Swimming pools, public (per person)
|
10
|
Theaters
|
|
-auditoriums (per seat)
|
5
|
-drive-in (per space)
|
10
|
Notes:
| |
---|---|
*
|
Number of seats shall be determined based on 15 square feet
per seat in service area.
|
Table 15.42.070
Septic Tank Capacity
| |||
---|---|---|---|
Single-Family Dwellings/Second Dwelling Units # of Bedrooms
|
Multiple Dwelling Units (1 bedroom each)
|
Maximum Drainage Fixture Units
|
Minimum Septic Tank Capacity4 (gallons)
|
1 to 61
|
2 to 3 units
|
33
|
1,500
|
-
|
4
|
45
|
2,000
|
-
|
5
|
55
|
2,250
|
-
|
6
|
60
|
2,500
|
-
|
7
|
70
|
2,750
|
-
|
8
|
80
|
3,000
|
-
|
9
|
90
|
3,250
|
-
|
102
|
1003
|
3,500
|
Notes:
| |
---|---|
1
|
Additional bedrooms, 150 gallons each.
|
2
|
Additional dwelling units, 250 gallons each.
|
3
|
Additional fixture units over 100, 25 gallons per fixture unit.
|
4
|
Septic tank sizes in this table include sludge storage capacity
and the connection of domestic food waste disposal units without further
volume increase.
|
Table 15.42.100
General Disposal Field Requirements
| ||
---|---|---|
Item
|
Minimum
|
Maximum
|
Number of drain lines per field
|
1
|
-
|
Length of each line
|
-
|
100 feet
|
Bottom width of trench
|
18 inches
|
36 inches
|
Spacing of lines, center-to-center
|
6 feet
|
-
|
Depth of earth cover of lines
|
12 inches
|
-
|
Grade of lines
|
Level
|
3 inches per 100 feet
|
Filter material under drain lines
|
121 inches
|
-
|
Filter material over drain lines
|
2 inches
|
-
|
Table 15.42.130
Wastewater Application Rates for Subsurface Drip Dispersal Fields
(Adapted from 2002 USEPA Manual Table 4.3)
| ||
---|---|---|
Soil Texture
|
Structure
|
Application Rate
(gpd/sf)
|
Gravelly coarse sand & coarser
|
Loose or cemented
|
0.0
|
Clay, sandy or silty clay silt loam
|
Weak or massive
|
0.0
|
Massive
|
0.0
| |
Sandy clay loam, clay loam or silty clay loam
|
Massive
|
0.0
|
Sandy clay, clay or silty clay
|
Moderate to strong
|
0.2
|
Sandy clay loam, clay loam or silty clay loam
|
Weak
|
0.2
|
Sandy clay loam, clay loam or silty clay loam
|
Moderate to strong
|
0.4
|
Sandy loam, loam or silt loam
|
Weak
|
0.4
|
Sandy loam, loam or silt loam
|
Moderate to strong
|
0.6
|
Fine, very fine, loamy fine and very loamy fine sand
|
Not Applicable
|
0.8
|
Coarse, single grain sand
|
Not Applicable
|
1.2
|