LIMITS OF ERROR, AND PENALTIES RELATED THERETO. Limits of error for the common dissolved constituents in aqueous samples are defined in the following schedule, which shall apply to the determination of satisfactory accuracy or precision in analyses for these components: Constituent Allowable Error Calcium 5% or 1.5 mg/1, whichever is greater Magnesium 6% or 1.5 mg/1, whichever is greater Sodium 5% or 2.0 mg/1, whichever is greater Potassium 5% or 1.0 mg/1, whichever is greater Chloride 5% or 1.0 mg/1, whichever is greater Sulfate 5% or 1.0 mg/1, whichever is greater Fluoride 10% or 0.1 mg/1, whichever is greater Boron 5% or 0.2 mg/1, whichever is greater Silica 10% or 2.0 mg/1, whichever is greater Nitrate + Nitrite as NO3 10% or 1.0 mg/l whichever is greater Total Phosphorus as PO4 20% or 0.20 mg/l whichever is greater Orthophosphate as P 20% or 0.20 mg/l whichever is greater Ammonia Nitrogen 20% or 0.20 mg/l whichever is greater Total Kjeldahl Nitrogen 20% or 0.20 mg/l whichever is greater Ag, As, Be, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Xx, Xx, Xx, Xx, Xx +25% for concentrations greater than or equal to 5X RDL (See Section 5) MBAS 25% for concentrations greater than or equal to 0.5 mg/l Organophosphorus Pesticides Concentrations cannot be beyond certified QC performance limits as provided by the reference material vendor SemiVolatile Organic Carbon and Polycyclic Aromatic Hydrocarbons Concentrations cannot be beyond certified QC performance limits as provided by the reference material vendor Oil & Grease Concentrations cannot be beyond certified Constituent Allowable Error QC performance limits as provided by the reference material vendor Ion Balance (Gen. Mineral) 0.5 milli-equivalents per liter or 5% whichever is greater
LIMITS OF ERROR, AND PENALTIES RELATED THERETO. Limits of error for the common dissolved constituents in “clean water” samples, i.e. those not admixed with large quantities of organic or inorganic detritus nor containing a large concentration of inorganic salts are defined in the following schedule, which shall apply to the determination of satisfactory accuracy or precision in analyses for these components: Constituent Allowable Error Calcium 5% or 1.5 mg/L, whichever is greater Magnesium 6% or 1.5 mg/L, whichever is greater Sodium 5% or 2.0 mg/L, whichever is greater Potassium 8% or 1.0 mg/L, whichever is greater Chloride 5% or 1.0 mg/L, whichever is greater Sulfate 8% or 2.0 mg/L, whichever is greater Nitrate 8% or 1.0 mg/L, whichever is greater Fluoride 8% or 1.0 mg/L, whichever is greater Boron 10% or 2.0 mg/L, whichever is greater Silica 10% or 2.0 mg/L, whichever is greater Phosphate 10% or 2.0 mg/L, whichever is greater Ammonia Nitrogen 10% or 1.0 mg/L, whichever is greater Total Kjeldahl Nitrogen 15% or 1.0 mg/L, whichever is greater Pb, Cu, Cr, Cd, Zn 10% at a detection limit of 20 g/L or greater Fe, Mn 8% at a detection limit of 100 g/L or greater Hg 25% at a detection limit of 1 g/L or greater Se, As 15% at a detection limit of 10 g/L or greater Pesticides, Herbicides 50% at a detection limit of 1 g/L or greater PCBs (PCP Group) 50% at a detection limit of 1 g/L or greater MBAS 100% Oil & Grease 100% Ion Balance 0.5 milliequivalents/Liter or 5% (General Mineral), whichever is greater Extractable Organics 50% of EPA established detection limits Volatile Organics 20% of EPA established detection limits In the case of analytical parameters not listed above, determinations of satisfactory accuracy and/or precision may be made by COUNTY, based on information in the latest edition of “Standard Methods,” or from other reputable publications. In the case of deviation from true values in excess of the detection limits outlined above, for samples of known composition submitted by COUNTY for accuracy quality control, COUNTY may (at its option) either: Notify CONTRACTOR, if COUNTY believes the error is of a random nature, or Submit to CONTRACTOR, for analysis, another sample of known composition. On the second occurrence of such excessive error within two consecutive quarters, CONTRACTOR’s invoices for one quarter shall be discounted in accordance with the following table: Average of Ratios of Errors to Allowable Errors % Discount
LIMITS OF ERROR, AND PENALTIES RELATED THERETO a. Determinations of satisfactory accuracy and/or precision may be made by County, on notification of Contractor, from information provided with Performance Evaluation samples from certified vendors. For samples prepared from Proficiency Testing (PT) standards, performance thresholds from the PT standard vendor will be used as the criteria for acceptability of results.
