Indah Water Konsortium Sdn Bhd (IWK), a national sewerage company, whollyowned by the Minister of Finance Incorporated, is responsible for providing sewerage services to 20 million users, operating and maintaining over 9,100 public sewage treatment plants and 16,000 km networks of sewerage pipelines, and providing scheduled desludging services to over 400,000 individual septic tanks in Malaysia since April 1994.