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The City of Grand Junction's Environmental Laboratory proudly
presents the 2007 Wastewater Quality Report

Utility and Street Systems Laboratories Environmental Laboratory Wastewater
Wastewater Services

Environmental Laboratory

Wastewater Definitions
2007 AVERAGES - WASTEWATER TREATMENT PLANT INFLUENT AND EFFLUENT

CITY OF GRAND JUNCTION ENVIRONMENTAL LABORATORY SERVICES DIVISION 
INORGANIC PARAMETERS
Influent Effluent Persigo NPDES Limit
Ammonia - Nitrogen 27.5 mg/L 7.3 mg/L Report 6
Chlorine Residual Not tested None detected 0.24 mg/L 1
Cyanide, Total None detected None detected Report 6
Dissolved Oxygen Not tested 5.5 mg/L Report 6
Nitrate - Nitrogen Not tested 10.6 mg/L Report 6
Nitrite - Nitrogen Not tested 1.8 mg/L Report 6
Oil and Grease Not tested None detected 10 mg/L1
pH 7.54 S.U. 7.12 S.U. 6.5 - 9.0 s.u. 1
Solids, Total Dissolved 774 mg/L 805 mg/L Report 6
Solids, Total Suspended 281 mg/L 5.0 mg/L 30 mg/L2
Solids, Volatile Suspended 219 mg/L 77 mg/L n/a
METALS
  Influent Effluent Persigo NPDES Limit
Antimony None detected None detected n/a
Arsenic 0.0021 mg/L None detected Report 6
Beryllium None detected None detected Report 6
Cadmium None detected None detected Report 6
Chromium 0.004 mg/L None detected Report 6
Copper 0.09 mg/L 0.003 mg/L Report 6
Lead 0.014 mg/L None detected Report 6
Mercury 0.0002 mg/L None detected 0.00045 mg/L 2
Molybdenum 0.01 mg/L 0.007 mg/L Report 6
Nickel 0.005 mg/L 0.002 mg/L Report 6
Selenium 0.004 mg/L 0.002 mg/L Report 6
Silver 0.004 mg/L None detected Report 6
Thallium None detected None detected Report 6
Zinc 0.15 mg/L 0.03 mg/L Report 6
       
BIOLOGICAL PARAMETERS
  Influent Effluent Persigo NPDES Limit
Fecal Coliform Bacteria Not tested 4 to 137 mpn/ 100 mL 5 2000 mpn / 100 mL 5
E. coli Bacteria Not tested 3 to 73 mpn / 100 mL 5 n/a
Whole Effluent Toxicity Not tested See Below 4 LC50>100%

P. promelas

Not tested None detected LC50>100%
C. dubia  Not tested None detected  LC50>100%
ORGANIC PARAMETERS
  Influent Effluent Persigo NPDES Limit
Biochemical Oxygen Demand 266 mg/L 12 mg/L 30 mg/L 2
Carbonaceous BOD Not tested 5 mg/L n/a
Phenol, Total 0.14 mg/L 0.01 mg/L n/a
Organochlorine Pesticides None detected None detected n/a
Polychlorinated Biphenyls None detected None detected n/a
Purgeable Organics See below See below n/a
Chloroform 0.006 mg/L None detected n/a
Synthethic Organic Compounds None detected See below n/a
bis(2-ethylhexyl)Phthalate
 None detected 0.048 mg/L n/a
RADIOLOGICAL PARAMETERS
Gross Alpha None detected None detected n/a
Gross Beta 13.2 pCi/L 12.8 pCi/L n/a
       
1 = Daily Maximum 4 = No pattern of toxicity detected. c = calculated limit   
 2 = 30-day Average 5= 30-day geometric mean (low to high range 2006) n/a = no USEPA limit   
3 = Geometric Mean
 
6= Report - No limit established for Persigo WWTP, but results must be reported to the USEPA. .    
       

This page updated Thursday, May 15, 2008

 
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