Is this non-compete valid?

My employer, for whom I have worked for over 2 years, just today presented me with an employment agreement to sign. Most of the terms are fine, but in the section on non-competition, I have some concerns. The section states that for a period of 1 year following termination of employment, whether said termination is voluntary or involuntary, that I cannot "directly or indirectly engage in any business with a customer that the employer is providing services to or potential customer with whom the employee was actively pursuing business on behalf of the employer." This limits the area of coverage to the Washington DC metro area, including Maryland, DC, and northern Virginia. It goes on to say "Directly or indirectly engaging in any competitive business includes, but is not limited to: i) engaging in a business as aowner, partner, or agent, ii)beoming an employee of any third party that is engaged in such business, iii) becoming interested directly or indirectly in such business, or iv) soliciting any customer of the employer for the benefit of a third party that is engaged in such business."

The problem with this is that my employer is a contractor for the Federal Government. This clause essentially locks me out of working for anyone if I want to continue in my same line of work, as even though it may be geographically restricted to the DC metro area, many federal agencies are based in DC with locations scattered around. Considering the size and scope of the federal government, it would be impossible to not cross paths with some common customer at some point.

Furthermore, should my employment terminate non-voluntarily, is this still valid? I really don't see how an employer can terminate someone's employment, and then prohibit them for seeking work elsewhere. I believe this non-compete is too broad in its scope, and unnecessarily restricts my ability to find work should my employment with my current company end.

Any guidance would be appreciated.