COMMON WATER QUALITY COMPLAINTS
COLOR GUIDE
WATER QUALITY REGULATION SECTION
CITY OF AUSTIN DRAINAGE UTILITY DEPARTMENT


COLOR/
APPEARANCE		 SMELL DESCRIPTION/ POSSIBLE SOURCE
Bright green
(or other bright,
unnatural color)		 None POSSIBLE SOURCES:
  • Uranine dye used in antifreeze (bright green).
  • Dye used for testing sewer lines, storm drains, ground water systems, etc. (usually green, blue, red, violet, etc.).
Red to orange to
purple (variable)		 None to slightly sweet or fermented DESCRIPTION
  • Found only in standing water.
  • Color is pH dependent.
POSSIBLE SOURCES:
  • Could be natural berry extract, look for berries such as mulberry, persimmon, etc.
Brown to gold, clear None DESCRIPTION
  • Found only in standing water.
  • Presence of leaves/organic matter in area.
POSSIBLE SOURCES:
  • Could be extract from decaying leaves.
Variable colored
scum floating on the
surface		 None to faint organic
solvent		 DESCRIPTION
  • Usually does not color the water.
POSSIBLE SOURCES:
  • Indicative of oil based paints that are immiscible with water.
  • Can also indicate spray paint sprayed directly onto the water surface. *This can cause some coloring of the water.
Dark green
(brown or golden)		 None
(sometimes musty)		 DESCRIPTION
  • Fibrous, slimy layers of algae, possibly with air bubbles in daylight hours.
  • Usually one predominant species of algae.
  • Convulsive, erratic swimming and lethargic behavior in fish.
  • Often associated with fish kills due to high pH (>9.5) and high dissolved oxygen.
POSSIBLE SOURCES:
  • Excessive algal growth most frequently caused by excess nutrients or fertilizers.
Brown, black or gray None
(or rotting organic
matter)		 DESCRIPTION
  • Usually observed in the evening and early morning hours.
  • Fish gasping and swimming at the surface.
  • Often associated with fish kills due to low dissolved oxygen (<2.0 ppm) with pH of 6.0-7.5.
POSSIBLE SOURCES:
  • Large amount of dying algae, frequently occurs after an algal bloom.
Yellow scum or suds None
(possibly pine-like)		 DESCRIPTION
  • Usually in stagnant water or nonflowing pools.
  • Typically in spring or summer.
POSSIBLE SOURCES:
  • Caused by pollen from flowering trees or evergreens (typically oaks or junipers).
Brown to off-white
and turbid or silty		 None POSSIBLE SOURCES:
  • Natural sediments in stormwater.
  • Excessive amounts in stormwater could indicate inadequate erosion controls at construction sites.
  • Sediments in nonstormwater runoff could indicate washing at construction sites.
White and cloudy (no
identifiable solids),
chalky where dry		 None DESCRIPTION
  • Suspended in flowing water, can settle out in still water.
  • Usually in an easy to follow trail to the source.
POSSIBLE SOURCES:
  • Typical runoff from concrete pouring, washing or cutting.
*White and cloudy (no
identifiable solids),
sometimes chalky
where dry
NOTE: color can
vary widely		 None or faint to
strong latex paint
smell		 DESCRIPTION
  • In flowing or standing water will mix through entire water column.
POSSIBLE SOURCES:
  • Typically runoff from the washing of painting equipment.
White and sudsy
(can sometimes be
bright green or blue
tinted.)		 Sometimes detergent
or cleaner smell
(may have a solvent odor.)		 POSSIBLE SOURCES:
  • Usually associated with home car washing or other detergent discharge.
  • Industrial strength floor cleaners, floor strippers and waxes usually form more tenacious suds.
Gray or black:
as film on surface or
scum on bottom, with
or without solids; can
also be clear with no
solids.		 Strong "sewer" or
ammonia odor		 DESCRIPTION
  • Usually easy to follow upstream to the source.
POSSIBLE SOURCES:
  • Indicative of sewage leak or overflow.
  • If solids are in the form of small "pellets", it could be bat guano (typically late spring to early fall).
Yellowish-brown,
lumpy and immiscible
in water		 Oily DESCRIPTION
  • Material clumps and can be somewhat frothy.
POSSIBLE SOURCES:
  • Usually caused by emulsified oil or lubricant.
Whitish to brownish,
lumpy or filmy		 Rancid cooking
grease		 POSSIBLE SOURCES:
  • Typically from a restaurant cooking grease bin or improper disposal and washing practices.
Dull sheen, swirls or
has plates when
disturbed		 None or rotting
organic matter		 POSSIBLE SOURCES:
  • Bacterial or fungal scum on the surface in standing water associated with decaying organic matter or fish kills.
Reddish-orange (or
iridescent) filmy scum
deposits or staining		 None DESCRIPTION
  • Usually at small seeps, springs or storm sewer outfalls.
  • Iridescent sheen is broken up into irregularly shaped "plates" when disturbed; does not swirl. (NOTE: If swirls, see rainbow sheen.)
POSSIBLE SOURCES:
  • Caused by high iron concentrations and iron bacteria.
  • In seeps and spring, it could indicate old landfills.
Rainbow sheen,
swirls when disturbed		 None to oil, gasoline
or diesel		 POSSIBLE SOURCES:
  • Typical in stormwater runoff from streets or parking lots.
  • In nonstormwater runoff, could indicate a petroleum spill.
Orange/brown with
thick floating mats;
rainbow sheen
present or absent		 None to a petroleum
or diesel smell		 POSSIBLE SOURCES:
  • Can be indicative of "old" diesel.
Rainbow sheen with
droplets colored red,
blue or yellow		 Diesel smell POSSIBLE SOURCES:
  • Diesel is now sold colored coded depending on federal fuel

    • taxes paid:
    red - for use off road in construction machinery or generators
    blue - for use in farm machinery
    yellow - for use as motor fuel on roads
    *purple, green, orange are obtained by illegally mixing fuels
  • If highly viscous and red, it could be transmission fluid.