STP Keylong phase I - Keylang, Himachal Pradesh Wastewater Treatment Plant

STP Keylong phase I is a wastewater treatment plant located in Keylang, in the Lahaul and Spiti district of Himachal Pradesh, India. It was designed to serve a small population of 310 people, reflecting the remote, high-altitude setting of the Himalayan region. The plant was designed for primary treatment only, with a capacity of 188 m³/day. Although currently non-operational, primary treatment typically involves physical processes like sedimentation to remove solids. In India, wastewater treatment for small communities is governed by the Central Pollution Control Board (CPCB) guidelines, which recommend appropriate treatment levels based on local conditions and receiving water sensitivity. The plant's discharge would have entered local streams that feed the Chenab River basin, ultimately draining into the Indus River system. The region's fragile Himalayan ecosystem relies on clean water for biodiversity and downstream communities, making proper treatment essential for environmental protection.

The plant is situated in the high-altitude Lahaul Valley, part of the Chenab River basin. Local streams from the Himalayas feed the Chenab River, which flows into Pakistan and joins the Indus River. The region supports sensitive alpine ecosystems, including snow-fed rivers and diverse wildlife, and any discharge must be carefully managed to avoid impacts on downstream water quality and aquatic life.