Patna, March 28: Overflowing drains during monsoon and pollutants flowing into Ganga from the overflowing sewers may soon be thing of the past.

Patna Municipal Corporation (PMC) is all set to spend a hefty amount in 2011-12 to upgrade the drainage system of the state capital.

Sources in the civic body said PMC had earmarked Rs 18 crore for maintenance and upkeep of the drains for the coming fiscal. It spent around Rs 39 lakh this fiscal for the purpose.

The reason for the almost 50 times increase in spending: the drainage system in the city is in a shambles and needs to be completely overhauled.

According to sources, only 30 per cent of the total number of household in the urban agglomeration areas is covered with the underground sewage system. This increases the dependence on septic tanks and low-cost sanitation systems.

“These systems support around 80 per cent of the households. They can pollute the shallow groundwater with microbial substance. Though a separate sewage system has been adopted in Patna, it does not function,” said a senior PMC official.

He added: “Storm water drains and open drains carry septic tanks effluent and untreated sewage. These must be treated properly. We will prepare a proper sewage plan for the city.”

Sources said the budget has been sent to the state government for approval. Once finalised, a detailed project report will be prepared.

The official said when the sewage network gets choked it usually gets connected to the storm drainage system.

“The drains get silted. This leads to a complete mess in the city. The drainage pumping stations in the city — at Pahari, Jogipur, Rajendra Nagar, Anta Ghat, Kishan Ghat, Mandiri, Mithapur, Rajapur, Punaichak, SP Verma Road and Kurji are old and not working to the designed capacity. The construction of unplanned colonies further aggravates the waterlogging. It has become a major health hazard,” said the official.

Sources said the Saidpur Pumping Station is catering to the central zone drainage system leading to a breach of Agamkuan drain.

“The Agamkuan drain is heavily silted. In the monsoon, the drain overflows and water accumulates in its catchment areas. Some of it finds its way back to the pump house at Saidpur. Encroachments, solid waste dumping and silt deposition cover the drainage channel. This leads to waterlogging in the area,” he added.

Till now Bihar Rajya Jal Parishad has been carrying out the infrastructure work related to the sewerage system and will later hand it over to the PMC for upkeep.

“As a large amount of money has been earmarked for strengthening of the system this year, PMC could start some infrastructure work. This would, however, depend on the sanction by the state government,” said a PMC official. He added that the multilateral agencies involved in planning, implementation, operation and maintenance has led to mismanagement.