FLOOD08209

• County: Adams
• County: Arapahoe
• County: Douglas, Jefferson
• Community: Denver Metroploitan Area
• Stream Name: South Platte River, Chatfield Dam to Baseline Road
• Basin: South Platte
• Title: Major Drainageway Planning
• Date: 8/1/1984
• Prepared For: Denver Metropolitan Area
• Prepared By: Wright Water Engineers, Inc.
• Contract/PO #: &&
• Floodplain - Doc Type: Floodplain Report/Masterplan

'Un-ionized ammonia calculated from total ammonia concentration and pH and
temperature conditions at the time of sampling.
'Geometric mean and arithmetic standard deviation reported.

'Un-ionized ammonia calculated from total ammonia concentration and pH and
temperatu re conditions at the time of sampling,
'Concentration at peak flow reported; only 4 of 9 storms had sufficient data
available for reporting.

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VI-14

TABLE VI-8 TABLE VI-9
(Reference 3) (Reference 3)
AMB I ENT STREAMFLOW STORM RUNOFF
CONCENTRATIONS MONITORED EVENT MEAN CONCENTRATIONS MONITORED
BETWEEN APRIL 1980 AND SEPTEMBER 1981 BETWEEN APRIL 1980 AND SEPTEMBER 1981
AT THE SOUTH PLATTE RIVER AT 50TH AVENUE AT THE SOUTH PLATTE RIVER AT 50TH AVENUE
Standard Standard
Water-Quality Variable Units Minimum Maximum Mean Deviation Water-Quality Variable Units Minimum Maximum Mean Deviation
Discharge (ft'/sec) 42.2 3.280 487 790 Storm Runoff Volume (10'ft') 10,2 94.3 43.1 25.4
Temperature (DC) 0.0 28 14 6 Temperature (DC) 13.0 19,6 16.7 2.5
pH (S.U.) 7.3 8.7 8.0 0.3 pH (S.U, ) 7.2 8.1 7.8 0.3
Dissolved Oxygen (mg/L) 5.2 12.4 8.6 1.6 Dissolved Oxygen (mg/L) 6.4 7.8 7.1 1.0
Total Suspended Solids (mg/L) 5.0 775 79 115 Total Suspended Solids (mg/L) 152 1,430 615 345
Total Organic Carbon (mg/L) 3.0 66 13 11 Total Organic Carbon (mg/L) 10 52 32 12
Total Nitrogen as N (mg/L) 0.4 11 5 3 Total Nitrogen as N (mg/L) 1 8 6 2
Total Ammonia as N (mg/L) 0.01 6.2 2.3 1.7 Total Ammonia as N (mg!L) 0,27 3.3 1.4 0.90
Un-ionized Ammonia as N' (mg/L) 0.003 0.03 0.08 0.08 Un-ionized Ammonia as N' (mg/L) 0.003 0,07 0.03 0.02
Nitrite as N (mg/L) 0.02 0.6 0.2 0.1 Nitrite as N (mg/L) 0.078 0.19 0.11 0,037
Nitrate as N (mg/L) 0.25 3.1 1.7 0.7 Nitrate as N (mg/Ll 0.82 2.6 1.2 0.54
Total Phosphorus as P (mg/L) 0.10 2.6 1.1 0.6 Total Phosphorus as P (mg/L) 0.51 2.0 1.4 0.45
Orthophosphate as P (mg/L) 0.01 2.4 0.8 0.5 Orthophosphate as P (mg/Ll 0.22 0.67 0.40 0.15
Biochemical Oxygen Demand (mg/L) 1 26 7 4 Biochemical Oxygen Demand (mg/L) 3,7 19 13 5.1
Chemical Oxygen Demand (mg/L) 12 116 29 15 Chemical Oxygen Demand (mg/L) 31 180 99 47
Fecal Coliform Bacteria' (#/loomL) 10 58,000 1,100 9.700 Fecal Coliform Bacteria' (::/loomL) 3.600 7,600 5.300 1,SOO
Total Hardness (as CaC03) (mg/L) 187 324 256 40 Total Hardness (as CaC03) (mg/L) 140 200 170 25
Chloride (mg/L) 16 324 63 39 Chloride (mg/L) 33 110 45 26
Cadmium, Total (llg/L) 0.5 21 3 3.0 Cadmium, Total (llg/L) 1.0 6.3 3.0 2.0
Cadmium, Dissolved (llg/L) 0.0 14 1 2 Cadmium. Dissolved (llg!L) 0.5 4.5 1.6 1.5
Copper, Total (llg/L) 5.0 120 29 22 Copper. Total (llg/Ll 28 99 63 25
Copper, Dissolved ( Ilg/L) 0.0 30 10 6.6 Copper. Dissolved (llg/L) 5.0 24 6.6 3.0
Iron, Total ( Ilg/L) 240 12,000 1,800 2,100 Iron. Total (llg/L) 2,800 27,000 11.000 8,200
Iron, Dissolved (llg/L) 5.0 330 37 58 Iron. Dissolved (llglL) 29 130 65 36
Manganese, Total (llg/Ll 40 440 240 81 Manganese, Total (llg/L) 160 990 550 280
Manganese, Dissolved (llg/L) 10 360 170 97 Manganese, Dissolved (llg/L) 44 190 110 52
Lead. Total (llg/L) 5.0 200 30 29 Lead. Total (llglL) 59 280 160 78
Lead, Dissolved (llglL) 0.0 30 9.7 5.6 Lead. Dissolved (uglL) 5,0 13 8.5 3.4
Zinc, Total (llg/L) 40 440 110 61 Zinc, Total (llglL) 94 480 280 130
Zinc. Dissolved (llg/L) 5.0 ISO 47 27 Zinc. Dissolved (ug/L) 22 51 38 10