Table 6.

Percentage and number of common water system components, materials exceeding 0.25% and 8% lead threshold by relative mass fraction (wt/wt).

Result	Water system components					Materials			Systems
	Foot valve ($n=25$)	Pump spout ($n=29$)	Rising main ($n=28$)	Pump rod ($n=28$)	Tap spout ($n=20$)	Brass ($n=36$)	Galvanized steel ($n=101$)	Stainless steel ($n=105$)	Systems with any component over 0.25% lead ($n=130$)
Samples exceeding 0.25% lead threshold	19 [76 (55–91)]	17 [59 (39–76)]	9 [32 (16–52)]	1 [4 (0–20)]	13 [65 (41–85)]	26 [72 (55–86)]	44 [44 (34–54)]	43 [41 (31–51)]	107 [82 (75–88)]
Samples exceeding 8% lead thresholda	17 [68 (46–85)]	0 [0 (0–12)]	5 [18 (6–39)]	1 [4 (0–18)]	1 [5 (0–2)]	11 [31 (16–48)]	23 [23 (15–32)]	21 [20 (13–29)]	76 [58 (49–67)]

^aAlthough 0.25% is the currently recommended threshold, plumbing codes used to reference an 8% maximum lead threshold prior to 2014.