Grassroots Rural and Small Community Water Systems Assistance Act - Calls for the Environmental Protection Agency (EPA) to prioritize the types of technical assistance to enable small public water systems to comply with national primary drinking water regulations that are the most beneficial to small and rural communities, based on their input.

Amends the Safe Drinking Water Act to: (1) authorize appropriations to the Administrator of EPA for FY2014-FY2019 for such assistance; and (2) allow the Administrator to use such funds to provide technical assistance to nonprofit organizations that provide to small public water systems onsite technical assistance, circuit-rider technical assistance programs, onsite and regional training, assistance with implementing source water protection plans, and assistance with implementation monitoring plans, rules, regulations, and water security enhancements. Directs the Administrator to give preference to nonprofit organizations that are determined to be the most qualified and experienced and that the small public water systems find to be the most beneficial and effective.