Proficiency Testing Ranges

Listed below are the analytes contained within each sample for proficiency testing. The method detection limits to be used for determining the levels of these analytes should fall between the low and high limits listed below.

Demand
PEI-026 WPCHEM
Study Type

Analyte	Low Limit		High Limit	Units
Biochemical oxygen demand (BOD) 1, 2, 3 1530	15.0	to	250	mg/L
Carbonaceous BOD (CBOD) 1, 2, 3 1555	15.0	to	250	mg/L
Chemical oxygen demand (COD) 1, 2, 3 1565	30.0	to	250	mg/L
Total organic carbon (TOC) 1, 2, 3 2040	6.00	to	100	mg/L

pH
PEI-027-3 WPCHEM
Study Type

Analyte	Low Limit		High Limit	Units
pH 1, 2, 3 1900	5.00	to	10.0	Units

Residue (Whole-Volume)
PEI-079 WPCHEM
Study Type

Analyte	Low Limit		High Limit	Units
Residue, total (TS) 1, 3 1950	140	to	675	mg/L
Residue-filterable (TDS) 1, 2, 3 1955	140	to	650	mg/L
Residue-nonfilterable (TSS) 1, 2, 3 1960	23.0	to	100	mg/L

Total Residual Chlorine
PEI-033 WPCHEM
Study Type

Analyte	Low Limit		High Limit	Units
Total residual chlorine 1, 2, 3 1940	0.500	to	3.00	mg/L

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Accreditied for study program by the following as indicated

1. NELAC
2. Other
3. A2LA