To amend the Safe Drinking Water Act to improve transparency under the national primary drinking water regulations for lead and copper, and for other purposes.

National Opportunity for Lead Exposure Accountability and Deterrence Act of 2017 This bill amends the Safe Drinking Water Act to require the Environmental Protection Agency (EPA) to revise the national primary drinking water regulations for lead and copper. The rule must direct: public water systems (the systems) to meet certain reporting requirements; the EPA to develop a sampling protocol and develop instructions for compliance with the protocol; the EPA, or the state exercising primary enforcement responsibility, to require on-site investigations for identifying the source of lead in all residential or nonresidential facilities when their individual samples have concentrations of lead or copper contamination exceeding specified levels; the systems to meet certain notification and reporting requirements when lead or copper concentration levels are exceeded; the systems to develop and make publicly available an inventory of the material composition of the service lines at residential and nonresidential facilities; the systems to collect and make publicly available information about the ownership of those service lines; and the systems to replace an entire lead service line (instead of partially replacing them) when they are replaced. The EPA must also revise the rule to lower the allowable level of lead that may be contained in drinking water.