South West Water has been told it needs to take action after the Environment Agency carried out more than 860 inspections of the company last year.
From those inspections, the water firm was given 250 actions it needed to carry out to make improvements.
Some of the issues found included missing, blocked or broken screens which prevent solid waste from entering the water and the risk of chopped sewage flowing into water during storms.
Inspectors also found leaking pipes, cracked tanks seeping liquids, and missing emergency pumps and generators. Monitoring equipment was faulty and general maintenance poor in places.
Just over three quarters of the sites were compliant.
Clarissa Newell, water industry manager for Devon and Cornwall at the Environment Agency, said: “These inspections are not new. They are essential health checks of the vital infrastructure that supplies clean drinking water and proper sewer systems.
“Officers have become frequent visitors to water company sites that perform essential jobs, their findings resulting in increased spending on improvements, modernised permits and even site pride.
“That said, when serious fault is found then enforcement will always remain an option to putting that right.”
Helen Wakeham, Environment Agency director for water, said: “In our role as regulators of the water industry, we are changing how we operate – with better data, our largest ever enforcement workforce and greater powers to do our job effectively.
“Inspections are a vital preventative measure, with our teams nationally issuing over 3,000 actions to water companies, including repairing sewage works and upgrading their infrastructure.
“Together, this will drive meaningful improvements in performance, hold persistent offenders to account and ultimately create a cleaner water environment.”
Richard Price, managing director of wastewater services at South West Water, said: “We have positively engaged with the Environment Agency this year to support each and every visit from our local officers, with three in four sites being recognised as fully compliant and no major or serious issues being raised across all sites visited.
“All other improvement actions are being tracked and fixed.”
