The most common problems encountered are listed below and are based on an informal survey of STPs (including Water Treatment plants also) carried out over the last 4 years.

Initial Start up of an STP failing to treat sewage: An STP is normally designed for the total sewage that can be expected when a building or premises is fully occupied. Full occupation in most cases usually takes up to a year or more. During this period when occupancy can be as low as 30% or so and gradually increases over a year or more, consequently the sewage that comes in initially does not provide the minimum load needed for satisfactory operation of an STP. It results in a situation which can only be called “sewage in sewage out”. Many STPs which face this situation take a long time to stabilize and provide treated sewage, very often, due to poor or wrong operation, STPs do not stabilize.

Poor design/under design of the STP : Often STPs which initially ‘struggle’ to overcome the FIRST PROBLEM described above also can not function because

the balancing tank is undersized

• aeration tank is undersized or clarifier is badly designed
• the total inflow of sewage is higher than the VOLUME the STP was designed to handle.

The tanks mentioned in 1) & 2) above are part of the primary and secondary treatment portions of an ASP system.Consistent mal-operation of the STP : Another very common feature is that a majority of plant operating personnel employed by agencies that take on Operation & Maintenance(O&M) contracts are illiterate, un TRAINED and supervised by people with LITTLE or no knowledge of what O&M involves. Such agencies generally charge O&M charges that residents’ associations consider affordable. Companies with well trained operation personnel and experienced supervisory staff charge for services an amount that reflect their skill and expertise which residents’ Associations are reluctant to pay and thereby lose out on a well run/operated water infrastructure. They often do not realize that even the charges which they consider as cheaper/lower are going to waste if the sewage is only partially treated.

Strong smell/odour from the STP: This is a very common complaint from numerous housing communities and even commercial buildings which have an STP in operation. The smell is often very strong and quite often unbearable. It is caused by any one or all of the problems listed above. 

Very high noise levels from the STP: Quite often residents of an apartment building have sought help from experts to minimize the very high noise levels from their STP which they find unbearable throughout the day and more so at night, thereby preventing the residents from sleeping in peace.

The most common problems encountered are listed below and are based on an informal survey of STPs (including Water Treatment plants also) carried out over the last 4 years.

Initial Start up of an STP failing to treat sewage: An STP is normally designed for the total sewage that can be expected when a building or premises is fully occupied. Full occupation in most cases usually takes up to a year or more. During this period when occupancy can be as low as 30% or so and gradually increases over a year or more, consequently the sewage that comes in initially does not provide the minimum load needed for satisfactory operation of an STP. It results in a situation which can only be called “sewage in sewage out”. Many STPs which face this situation take a long time to stabilize and provide treated sewage, very often, due to poor or wrong operation, STPs do not stabilize.

Poor design/under design of the STP : Often STPs which initially ‘struggle’ to overcome the first problem described above also can not function because

the balancing tank is undersized

The tanks mentioned in 1) & 2) above are part of the primary and secondary treatment portions of an ASP system.Consistent mal-operation of the STP : Another very common feature is that a majority of plant operating personnel employed by agencies that take on Operation & Maintenance(O&M) contracts are illiterate, un trained and supervised by people with little or no knowledge of what O&M involves. Such agencies generally charge O&M charges that residents’ associations consider affordable. Companies with well trained operation personnel and experienced supervisory staff charge for services an amount that reflect their skill and expertise which residents’ Associations are reluctant to pay and thereby lose out on a well run/operated water infrastructure. They often do not realize that even the charges which they consider as cheaper/lower are going to waste if the sewage is only partially treated.

Strong smell/odour from the STP: This is a very common complaint from numerous housing communities and even commercial buildings which have an STP in operation. The smell is often very strong and quite often unbearable. It is caused by any one or all of the problems listed above. 

Very high noise levels from the STP: Quite often residents of an apartment building have sought help from experts to minimize the very high noise levels from their STP which they find unbearable throughout the day and more so at night, thereby preventing the residents from sleeping in peace.