Northeast's 1st Sewage Treatment Plant Starts Functioning in Manipur With a project cost of Rs. 345 crore, Imphal Sewerage Project phase 1 has a generating capacity of 27 million litres per day and will cover areas of Imphal IMPHAL: In a welcoming move, Manipur gets its first-ever sewage treatment plant in Northeast India. The sewage treatment plant located in Manipur's Imphal is made at a total of Rs 345 crore and was commissioned in June 2020 after a trial run was conducted for one-and-a-half years. Earlier, the Manipur state government under the banner of Imphal Sewerage Project phase 1 in Imphal to control pollution gave a green signal to the plant.