Footer on site with all areas covered?

Hi all Just wondering what the consensus is on this one. We are an electrical business and a lot of customer searches include the area the are within. I.e electrician in Greenwich For this reason we have created various pages for these areas I.e electricians in Greenwich We create a lot of blog content and also have various service type pages. It seems to me to be a no brainer to include a footer on each page which states each area we cover I can’t see this having a detrimental effect on SEO unless missing something? Thanks