Bathing waters at St Annes North are currently rated adequate, the lowest on a three star scale.
Mr Menzies said: “These are two very serious reports in the space of two weeks.
“Tourism is massively important to St Annes and to Fylde and the beaches are one of our most important assets.
“I am very worried about the condition of the bathing waters and about the timing of these reports ahead of a busy summer season.
“I have asked United Utilities and the Environment Agency to look into what is causing these issues, as matter of urgency and want to know what plans they have in place to solve these problems and to ensure the water is clean and safe for all.”
Mr Menzies is supporting Government action to clean up rivers and coastal waters and to end the discharge of waters from storm overflows.
Earlier this year the Government published the Storm Overflows Discharge Reduction Plan which marks a step change in how water companies tackle the number of discharges of untreated sewage.
He said: “We need to make sure water companies are delivering the investment and upgrades necessary to prevent pollution of our rivers and coastal waters.
“Given the scale of the challenge I realise things cannot change overnight.