Humboldt Bay Municipal Water District Testing:                                                                                McKinleyville Community Services District        

                                                                                                                                                                                                2006 Consumer Confidence Report


Contaminant and Units

Level Detected

MCL

PHG (or MCLG)

Likely Source and Potential Effects (if above MCL)

Microbiological Contaminants

Total Coliform Bacteria

Zero positive

More than one positive sample monthly

Zero positives

Coliform bacteria naturally present in the environment and are used as an indicator that other potentially-harmful, bacteria may be present

Fecal Coliform and E. coli.

Zero positive

A routine sample and a repeat sample are total coliform positive, and one is also fecal coliform positive

Zero positive

Fecal coliform and E. coli. are bacteria whose presents indicates that water may be contaminated  with human or animal fecal waste

Disinfection Byproducts and Disinfectant Residuals

TTHMs – Total

Trihalomethanes (ppb)

Average = 6.0

80 mg/L

n/a

By-product of drinking water chlorination

   HAA5 (ppb)

 Halo acetic Acids

Average = 2.4

60 mg/L

n/a

By-product of drinking water chlorination

   Chlorine (ppm)

Average= 0.65

4 mg/L

4

Drinking water disinfection

Inorganic Contaminants

Copper (ppm)***

Five sites tested and none were above the AL; 90th percentile= .665 

AL = 1.3 mg/L

0.17

Internal corrosion of household plumbing; erosion of natural deposits; leaching from wood preservatives

Lead (ppb)***

Five sites tested none above the AL 90th percentile= ND

AL = 15 mg/L

2

Internal corrosion of household plumbing systems; discharges from industrial manufactures, erosion of natural deposits

Aluminum (mg/L)

0.16

0.2 mg/L

N/a

Discharges from industrial manufactures, erosion of natural deposits

Regulated Contaminants with Secondary MCLs

(as defined above, secondary MCLs address aesthetic quality of the water such as odor, taste, and appearance)

Chloride (ppm) *

Range = 3.0 – 3.0

Average = 3.0 

500 mg/L

n/a

Runoff/leaching from natural deposits, or seawater influence

Sulfate (ppm) *

Range = 10.2 – 10.2

Average = 10.2

500 mg/L

n/a

Runoff/leaching from natural deposits; industrial wastes

Specific Conductance

(micromhos)**

Range = 169 – 188

Average 178.5

1600 mmho/cm

n/a

Substances form ions in water

Total Dissolved Solids

(ppm) *

Detected Level = 96-98

Average = 97

1000 mg/L

n/a

Runoff/leaching from natural deposits

Turbidity

 (NTU)