DRAINAGE SYSTEM
4 Sub-systems:
1. Soil Drainage System
- Conveys Discharge carrying fecal matter.
2. Waste Drainage System
- Conveys Discharge from plumbing fixtures other than water closet or similar
fixtures. No Fecal Matter.
- Also known as Sanitary Drainage System.
3. Storm Drainage System
- Receives clear water from leaders, downspouts, roof, surface run-off, ground
water, subsurface water, condensate water, cooling water, or similar kind of
discharge.
- Sanitary discharge excluded.
4. Vent System
- Piping system that received flow of air to or from a drainage system. Provides
circulation within such system to prevent siphonage or back pressure.
REQUIREMENTS for a PROPERLY DESIGNED DRAINAGE SYSTEM

Must be AIR TIGHT, GAS TIGHT, AND WATER TIGHT.

Shall be provided with separate trap, other than those with built-in / integral traps.
Prevents odor-laden and germ-laden to rise out of the drainage system.

Each plumbing fixture shall be provided with vent pipes.

Cleanout that is easily accessible shall be provided for maintenance of a pipe run.
1. Upper end of every stack.
2. Every change in horizontal direction. Not more than 22.5 degrees.
3. 1.5m (5’) inside the property line. Before House sewer connection.
4. Every 15m (50’) horizontal pipe run.

Horizontal pipe run shall be in slope of not less than 2%.

Horizontal pipe shall be supported and anchored at intervals not to exceed 3m.

Vertical pipe shall be secured at close interval. Stacks shall be properly supported
at their bases.