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4.0 Domestic Wastewater Characteristics

The following are general characteristics for domestic wastewater. The regulations covering the sizing of on-lot disposal systems are based on the assumption that the wastewater is similar to domestic wastewater . Therefore, it may be necessary to provide additional pretreatment or enlarge the on-lot disposal system for higher strengthen wastewaters, such as: restaurants, breweries, nursing homes, hospitals, etc.

Table 1.
Typical Characteritics of Domestic Wastewater
Parameter
Typical Concentration
Total Coliform
1 billon to over 100 billion per liter
Fecal Coliform
100,000 to 1 billion per liter
BOD 5
200 to 290 mg / L
COD
680 to 730 mg / L
Total Nitrogen
35 to 100 mg N /L
Ammonia
6 to 18 mg N /L
Nitrate + Nitrite
< 1 mg N / L
Total Phosphorous
18 to 29 mg P / L
Ortho Phosphorous
6 to 24 mg P /L
Total Solids
680 to 1000 mg / L
Volatile Solids
380 to 500 mg / L
Suspended Solids
200 to 290 mg /L
Volatile Suspended Solids
150 to 240 mg /L

Source: US EPA, Design Manual: Onsite Wastewater
Treatment and Disposal Systems, October 1980.

Table 2.
Pollutant Concentration of Major Components
of Residential Wastewater in mg / L
Parameter
Garbage Grinders
Basin/Toilet
Sink/Appliances
Combined Wastewater
BOD5
2380
280
260
360
Suspended Solid
3500
450
160
400
T. Nitrogen
79
140
17
63
T. Phosphorous
13
20
26
23

Source: US EPA, Design Manual: Onsite Wastewater
Treatment and Disposal Systems, October 1980.