New Delhi, April 17 -- After two decades and more than Rs.2,454 crore poured into the Delhi Jal Board's (DJB) flagship Interceptor Sewage Project (ISP), a significant chunk of that investment appears to have effectively gone down the drain. An inspection ordered by the Centre has found that the project stopped only 60% of the sewage volume DJB claimed to have halted from entering the Yamuna. The ambitious project, launched in 2006, was designed to intercept smaller drains feeding the Yamuna and divert raw sewage to sewage treatment plants (STPs). But a series of inspections carried out in February this year by the Delhi Pollution Control Committee (DPCC) on the orders of the Centre found large-scale discrepancies in DJB's performance data....