Issues with interfering peak in GC-FID method for determining residual ethanol content

I am attempting to adapt an alcohol congeners GC-FID method that uses a CP Wax 57CB column to measure residual ethanol levels (<1%) in pot ale samples. The congeners method has the ability to measure ethanol, however at low quantities the peak area is very small and as a result any peak at the retention time of ethanol in the blank would lead to void results.

When I ran water as a blank (The matrix of the ethanol standards), a small peak appeared at the same retention time as the ethanol peak in the standards and it is of similar area to the lowest calibration standard. I have tried our site's deionised water from a tap, as well as bottled HPLC Grade water and both samples contain this peak and I am unsure what the peak relates to or how it could be resolved by changing the method parameters.

Any help would be appreciated

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