How Your Sanitations System Works

Your Home Plumbing System

For the most part you do not see it; think about it; or worry about it until something goes wrong. Within your home's walls, floors and in the yard lays your home plumbing system. At first glance, it may seem to be a complex system of pipes, fittings, valves and fixtures that seem to go in every different direction but your home plumbing system is actually rather simple and straightforward.

A home plumbing system is made up of three basic components:

• A fresh water supply system
• Appliances and fixtures, and
• A drain system

Once the main water supply line has entered the home, it splits off and a pipe runs to the hot water heater. From the hot water heater, a hot water line parallels the cold water line to supply sinks, showers, bathtubs, clothes washers, and dishwashers. Toilets and outside faucets are supplied by cold water lines only. The water supply to the home's fixtures and appliances is then controlled with faucets and valves. Any water used in the home and not consumed enters the drain system and now is known as "Wastewater."

In order for wastewater to be safely removed from your home, it must first flow through a trap, a U-shaped pipe that holds standing water and prevents sewer gases from entering your home. This trap is also called a "P" trap due its shape. The pipe exiting the trap must be angled slightly downward to facilitate the flow of wastewater into the drain system. If a drain line is not used for a lengthy period of time, these traps may become dry and sewer odors can enter your home. All you need to do is to pour water into the drain to refill the trap and eliminate the odor. By state and local plumbing codes, every fixture must have a drain trap.

So how does the wastewater leave the home? Are there pumps in the house? The drain system within your home works entirely by gravity thus allowing wastewater to flow downhill through a series of large diameter pipes. Therefore, no pumps are needed. The drainpipes are also connected to a vent pipe system running up through the roof that brings fresh air to the drainpipes, preventing suction that would either stop or slow the free flow of wastewater. The vent pipes are important and you must take care to ensure that these roof vents do not become clogged resulting in slow drains or backups. Two of the most common ways the vent pipes become clogged are bird nests and leaves.

All of the wastewater generated within your home flows to the main waste and vent stack. The main vent stack curves to become a sewer line that exits the house near the foundation. This line is known as your sewer service line. Each service line then runs to a collector sewer line in the street or in the rear of the home. There are a few areas where sewer service is not available, and these homes have their sewer service lines running to a septic system. In simple terms, a septic system is a mini-wastewater treatment system designed and engineered for an individual home to treat, neutralize, stabilize or dispose of sewage. The final piece of the wastewater drainage system for your home is a ground level Y-cleanout, or two-way cleanout, which allows blockages to be more easily removed.

How Your Toilet Works

In fact, you can find one of these fixtures in just about every home in the U.S. If your home is new, you most likely have more than one. In fact, the number of these fixtures is always a selling point for a home.

So how does a toilet really work? When the handle is pushed down the lift lever raises a rubber seal called a flapper or tank ball. Water in the tank rushes down through the flush valve opening in the bottom of the tank into the toilet bowl. Wastewater in the bowl is forced through the trap into the main drain. When the toilet tank is empty, the flapper seals the tank and a water supply valve, called a ballcock , refills the toilet tank. A float ball that rides on the surface of the water controls the ballcock . When the tank is full, the float ball automatically shuts off the ballcock .

The two most popular types of ballcock assemblies are shown here. The plunger type has a float arm, which applies pressure on a valve and plunger to seal off the incoming water. The simpler, easy to install, flat-cup type has no float arm or ball. The plastic cup or fill valve functions to control the water flow.

Plumbing Problem, What Could be the Cause?

For the most part you do not see it; think about it; or worry about it until something goes wrong. As Murphy's Law would have it, you most likely will have a plumbing problem some time.

Why would your sink, tub, shower or toilet drain very slowly?

    There are several possibilities:

• The vent system could be obstructed,
• The "P" trap may be clogged,
• There could be a partial obstruction in the line between the individual facility and the main drain, or
• The main drain could be partially obstructed.

    If only one facility does not drain:

• The problem lies somewhere between the facilities and the main drain.

    If more than one, but not all of the facilities, do not drain properly:

• Then the problem lies somewhere within your home's internal plumbing system. 

    If no facilities drain properly:

• The problem can be either in the main drain within the house or in the property's service connection that connects the home to the main sewer line.

    Obstructions in the property service connection can result from:

• Grease buildup,
• A solid object flushed into the drain line,
• A caved in line,
• A swag (dip) in the line that allows solids to settle out and eventually obstruct the line, or 
• Roots in the line that have entered at unsealed joints, slipped joints or cracks in the pipe.

What can you do to help prevent plumbing problems?

• Never flush or dump solid objects, hair, cloth, grease or animal fats into your drain system.
• You should not plant trees over or near the property service connection.

What steps should you take if you experience problems that you cannot take care of yourself?

• The homeowner is responsible for the service line from the house to the main line however, if you have any questions, you may contact the Northwest Lakewood Sanitation District.
• You should contact a plumber that handles wastewater collection services lines to assist you in resolving the problem.

Components of a Wastewater Collection System

BUILDING SEWERS, also known as PROPERTY SERVICE CONNECTIONS ( PSCs ), are what connect a building's internal wastewater collection system to the municipal sewer system. PSCs can connect to a lateral, main or trunk sewer line.

LATERAL & BRANCH SEWERS are the upper ends of the municipal sewer system. Laterals dead-end at their upstream end with branch sewers collecting the wastewater from several lateral sewer lines.

MAIN SEWERS are collectors for numerous lateral and branch sewers from an area of several hundred acres or a specific neighborhood or housing development. They convey the wastewater to larger trunk sewer lines, to lift stations or to a neighborhood package wastewater treatment plant.

TRUNK SEWERS serve as the main arteries of the wastewater collection system. They collect and convey the wastewater from numerous main sewer lines either to a wastewater treatment plant or to an interceptor sewer.

INTERCEPTOR SEWERS receive the wastewater from numerous trunk sewers and convey it to a wastewater treatment plant. These are the largest diameter lines in the sewer system and the furthest downstream in the system.

LIFT OR PUMP STATIONS are utilized in gravity sewer systems to lift (pump) wastewater to a higher elevation when the route followed by a gravity sewer would require the sewer to be laid at an insufficient slope or at an impractical depth. Lift stations vary in size and type depending upon the quantity of wastewater to be handled and the height it must be lifted.

Grease Interceptors and Grease Traps

A grease control programs intended use is to reduce and/or eliminate in most cases Fats, Oils & Grease (FOG) from entering into the wastewater collection and treatment system.

There are two (2) types of passive devices that are used to collect FOG an Interceptor or Trap. An interceptor is a large below ground two compartment tank. Interceptors are larger than traps and are installed underground, outside of a facility. Grease is actually "intercepted" in these concrete tanks before it reaches the District's sewer main. Grease interceptors should be accessible by three manhole covers, and a sample box.

A grease trap is usually indoors "under the sink" and is a two compartment tank. The Uniform Plumbing Code (UPC) requires that an interceptor be installed where food is prepared. The trap prevents excess grease from getting into the sewer system from existing plumbing lines within facilities.

Interceptors and traps cause the flow of water to slow down, allowing the grease to naturally float to the top of the tank for easy removal.

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