The Clean Air Act defines an area as attainment or nonattainment based on a “design value” (see Criteria Pollutants). Please read below for information about lead attainment status and design value trends.
New Hampshire’s Attainment Status
New Hampshire is currently designated as attainment statewide for lead. Because there has never been a nonattainment designation for lead in New Hampshire, there are no maintenance areas.
Since NHDES began monitoring lead, concentrations have remained well below the NAAQS. The current design value for lead is defined as the maximum rolling three-month average over a three-year period plus the two months preceding this period. Maximum design values for New Hampshire have been equal to zero mg/m3 since 2012; the current NAAQS for lead is 0.15 mg/m3.