For the study of electromagnetic waves in a 2D environment, the Helmholtz equation can be reformulated in boundary integral form by the so-called Contour Integral Method (CIM). The influence of uncertainty in the geometry is studied via Polynomial Chaos Expansion (PCE). A distinction is made between the so-called intrusive and non-intrusive PCE. Both methods are applied to the CIM and compared to each other and to Monte-Carlo simulation (MC).