being introduced into a collection system at their source.
Industrial wastes can also be very high or low in pH because of acids and/or bases used in their processes. You may expect intense colors in wastes from painting areas. Grit, salt, and dirt levels may be high from vehicle wash racks. Radioactive wastes must never be dumped into. regular collection systems. They must be handled separately and, in most cases, very carefully. Explosive or flammable liquids can often enter the system from fuel storage areas. These liquids also create a dangerous fire hazard in a sewage treatment plant.
Storm water should be excluded from the sewage collection system as much as possible. Heavy input of storm water can disturb the operation of a treatment plant by sending it too much water, a problem called hydraulic overloading. This situation may force diverting or bypassing effluent from the treatment plant. Bypassing is normally a violation of National Pollutant Discharge Elimination System (NPDES) permits. These permits are controlled by the Environmental Protection Agency (EPA). Bypassing can result in releasing bacteria, heavy metals, and other dangerous contaminants into receiving waters. It is to be avoided whenever possible.
Very large paved or roofed areas should not be drained into the sanitary collection system. Maintenance personnel should prevent storm-water infiltration as much as possible by ensuring manholes are sealed, pipes are not cracked or broken, and all leaking joints are repaired.
Each military installation has different wastewater flows depending upon the types or
Table 10-1. - Characteristics of Typical Wastewater Generated at Military Facilities
Parameter | Weak | Medium | Strong |
Total solids | 330 | 700 | 1,200 |
Total volatile solids | 240 | 420 | 810 |
Suspended solids | 100 | 200 | 400 |
Total dissolved solids | 230 | 500 | 800 |
Volatile suspended solids | 70 | 130 | 220 |
Settleable solids* | 2 | 4 | 6 |
Biochemical oxygen demand (5 day) | 100 | 200 | 400 |
Total nitrogen as N | 10 | 20 | 40 |
Ammonia nitrogen as N | 4 | 10 | 20 |
Total phosphorus as P | 6 | 10 | 20 |
Grease | 50 | 100 | 150 |
Chemical oxygen demand | 300 | 450 | 600 |
*All the above are measured in milligrams per liter (mg/I) except settleable solids, which are measured in milliliters per liter (ml/I).
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