Oldham Treatment Process

The Oldham treatment process is accomplished in 4 steps.

The Oldham Sewage Treatment System utilizes the extended aeration process which treats sewage by stabilization of organic matter. This is achieved by thoroughly mixing fresh and treated sewage in an oxygen saturated environment combined with continuously controlled sludge return. Extended aeration of the recirculating solids produces a clear odorless effluent.

The first compartment, 400 gallons capacity, receives the raw sewage from the house. All foreign matter and heavier solids settle in this compartment. The solids which will decompose in water (comprising more than 99% of the solids) together with the liquid waste, then pass through a vitrified elbow into the second compartment.

In the second compartment, air, which is supplied by a positive displacement type pump located in a riser on top of the tank, is discharged into the contents of the compartment near the inlet wall and near the bottom of the tank. The discharge of air at this point causes the liquid in the compartment to circulate or roll with sufficient force that all of the solids in the sewage are maintained in suspension in the liquid. Oxygen in the solution creates an environment favorable to the growth of aerobic bacteria. These microscopic organisms digest the solids in the sewage within the period of 24 hours. The capacity of this compartment is 600 gallons, more than the daily treatment capacity of the system. The average sewage flow from an individual residence is 400 gallons per day.

Backwash water containing salt from water softener should by-pass waste water systems.

The third component is the clarifier. When the contents of the aeration compartment enter the clarifier, the treated solids, no longer subjected to the rapid circulation of the aeration compartment, settle to the bottom of the clarifier and return to the aeration compartment by gravity through a slot, where they are further digested. The lighter solids, which will float, are returned to the aeration compartment by means of a skimming device located at the surface of the liquid. Clear liquid is discharged from the clarifier form a point 2” below the surface of the liquid, through a vitrified elbow, and then carried to the point of discharge through the effluent pipe.

Ground water from basement drain tiles and storm water must not be discharged into the system, as it will create an hydraulic overload, which will destroy the aerobic digestion process.

Any discharge of wastewater in excess of the rated capacity should be avoided.

The fourth step in the treatment process is accomplished in the aerated up-flow filter (not all systems have this step). The effluent form the clarifier of the aeration tank enters the filter and is discharged downward through a 4” pipe into the bottom compartment of this tank where more of the suspended solids settle, and are retained for periodic removal by pumping.

The liquid in the upper part of this settling compartment is forced upward, by the incoming liquid, through narrow slots in a concrete slab which supports the filter media. As it rises above the filter media, post aeration is accomplished by introducing air from the blower on the aeration tank, through a diffuser pipe. Post aeration improves the quality of the effluent by further reduction of the suspended solids, and B.O.D. (strength), and increasing the dissolved oxygen before discharge.

Peak flows should not exceed one-third of the total daily flow (133 gallons) in any three-hour period.

To conform to the testing procedures, under which all individual residential aerated sewage treatment systems are tested, sufficient air for the aerobic digestion process, circulation of the contents of the aeration compartment and post aeration of the effluent, is supplied by a motor and blower unit which delivers 14 cubic feet of air per minute at 2 pounds pressure. To properly treat the wastewater of an average household the ½ horsepower motor will consume 85 to 90 kilowatts of electricity per month.

The motor is controlled by a timer and is set to operate the necessary length of time to properly treat the sewage. This operating time will vary depending upon the amount of sewage to be treated each day. An undersupply of oxygen retards the aerobic digestion process and will result in a septic condition, which will cause an offensive odor. An oversupply of oxygen will result in too much aerobic digestion and the solids will become too light to settle and will be discharged with the effluent.

Therefore, it is necessary to maintain the correct amount of oxygen in the contents of the aeration compartment. The proper oxygen content can be readily determined by noting the color of the contents, which should be a chocolate brown.

ELECTRIC CONTROLS

The 120-volt motor is protected by a fuse and warning light, located under the fiberglass dome of the equipment riser. In the event that the fuse burns out, the red warning light will glow, indicating that the motor is not operating and service is necessary. (Some systems do not have this.)

The service company’s name is often attached to the aerator motor. The homeowner is requested to notify the service company should service to the system be required.

To Prevent Malfunction Of Your Sewage Treatment System
The Following Materials Should NOT Be Discharged Into The Sewer:

Plastic Materials (including condoms)
Tampons, tampon applicators, sanitary pads, etc.
Cloth
Large quantities of acids or caustics – soaps or cleaning materials, which have a high or low pH factor
Cigarette stubs
Disposable diapers
Rubber Products
Paper Towels
Tissues
Grease or fatty materials
Oily materials, motor oils, grease, kerosene, gasoline, paints, etc.
Any material which does not disintegrate or dissolve readily
Backwash water from water softeners
Sump pump discharge

The use of bio-degradable and low suds laundry soaps is strongly recommended.

EXCESSIVE USE OF WATER IS HARMFUL TO THE SYSTEM