As of January 2018, updated standards require all federal agencies and contractors to create web content accessible to all.
I did a bit of research and found some basic steps to asses a site for ADA compliance.
- Review the Website Content Accessibility Guidelines (WCAG 2.0). A lot of content but I scanned the overview list.
 - Conduct an audit of the site using a WAVE Web Accessibility Tool. Plug in the url of your site and it tags areas of issue. This was very helpful to see what I was facing.
 - Make sure your site has alt tags on all images, videos, etc., describing the content.
 - Review the site’s styles and elements, such as and make sure styled content is readable and legible.
 - Utilize writing for best usability keeping content simple and scannable. Use text h tags to establish hierarchy of importance.
 - Audit the site’s code and bring it up to date.
 
Keeping a site compliant is not a one-time fix. Keep all new content optimized for ADA usability.