Shimla: The 1,500 MW Nathpa-Jhakri Hydro-Electric power project remained shut for the fifth consecutive day on account of high silt level, hampering power supply to seven northern States. The silt level was recorded 5,500-6,000 particles per million (ppm) on Sunday, which is higher than the permissible 4,000 ppm, forcing closure of the project for fifth day, Deputy General Manager of public sector Satluj Jal Vidyut Nigam (SJVN) told PTI. Closure of NJHEP, the largest underground hydro-electric power project in the country commissioned by the SJVN, has affected supply to northern States -- Punjab, Haryana, Uttar Pradesh, Uttaranchal, Rajasthan, Delhi and Himachal Pradesh. The six units of 250 MW each of NJHEP were closed on June 11 last as a precaution, SJVN spokesman Vijay Kumar Verma told PTI. Sand and stone particles mixed silt is coarse and it can damage the machines, he said. The high silt level has been caused by the Spiti, a tributary of the Satluj. He said nothing can be done in this condition except wait for the water flow to come to a permissible level. Due to the stalling of the project, the corporation, a joint venture of the Centre and the State Government, is losing about Rs 9 crore daily.