1. WATER AND WASTE WATER
ANALYSIS (BIOLOGICAL
PARAMETERS)
By: Marlisa Sau
Nur Hayati Yusoff
Norfarrahdilah Amir
Siti Salwa Abdullah

2. Objectives
• To compare several differences in biological
characteristics of water samples
• To learn the technique for evaluating water
quality in term of biological parameters.

3. Heterotrophic Plate Count
• The Heterotrophic Plate Count (HPC) is a procedure
used to estimate the number of live heterotrophic
bacteria that are present in a water sample.
• A sample of water is put on a plate that contains
nutrients that the bacteria need to survive and grow.
• Each colony-forming unit represents an initial
single, live bacterium that was capable of multiplying
until it could be observed on the plate.
• Colony count serves as a relatively easy way to
measure filtration and disinfection efficiency, as well as
the estimated numbers of bacteria in areas that have
the potential for increased contamination.

4. Results: Sample B
Plate 1 Plate 2
10¯¹ 10¯²
Plate 3 Plate 4
10¯³ 10¯⁴

5. Plate 5
10¯⁵
Plate 6
10¯⁶
Plate 7
10¯⁷

6. Table 1
PLATE NUMBER OF COLONY
Sample A Sample B
10¯¹ 90 colonies 33 huge colonies
10¯² One huge colony 19 colonies
10¯³ One huge colony Too many to count
10¯⁴ No colony 55 small colonies
10¯⁵ No colony 10 colonies
10¯⁶ No colony None
10¯⁷ No colony None

7. Calculations
• Sample A
1. 90/1ml x 10¯¹ = 9CFU/ml
• Sample B
1. 33/1ml x 10¯¹ = 3.3 CFU/ml

8. 2. 19/1ml x 10¯² = 0.19 CFU/ml
3. 55/1ml x 10¯⁴ = 3.55 x 10¯⁴ CFU/ml

9. Discussion
• The recommend HPC levels should not exceed
500 CFU/ml.
• The lower the HPC, the better the biological
water quality.
• The test does not specify the organisms that are
detected in samples.
• Micro organisms recovered through HPC tests
generally include those that are part of the
natural (typically non-hazardous) microbial flora
found in water.

10. Common bacterial species detected in drinking
water
Bacterial Species Infectious Dose (Ingested)
Pseudomonas aeruginosa 108-109 CFU
Aeromonas hydrophila >1010 CFU
Mycobacterium avium 104-107 CFU
Xanthomonas maltophila 106-109 CFU

11. Precautions
In order to ensure that re-growth of bacteria is
kept to a minimum,
• maintenance protocols
• regular cleaning
• temperature management
• maintenance of a disinfectant residual such as
chlorine

12. Standard Total Coliform Fermentation
• The coliform group consists of several genera
of bacteria belonging to the family
Enterobacteriaceae.
• When multiple tubes are used in the
fermentation technique, results of the
examination of replicate tubes and dilutions
are reported in terms of the Most Probable
Number (MPN) of organisms present.

13. • This number, based on certain probability
formulas, is an estimate of the mean density
of coliforms in the sample.
• Coliform density provides the best assessment
of water treatment effectiveness and the
sanitary quality of untreated water.

14. Results: Sample A
Test tube Sets
1st 2nd 3rd
10¯¹ + + + 3
10¯² + + + 3
10¯³ - + + 2 0.93 X
10³MPN/ml
10¯⁴ - - - 0
10¯⁵ - - - 0
10¯⁶ - - - 0
10¯⁷ - - - 0

15. Results: Sample B
Test tube Sets
1st 2nd 3rd
10¯¹ + + + 3
10¯² + + + 3
10¯³ + + + 3
10¯⁴ + + + 3
10¯⁵ + - + 2 0.93 X
10⁵MPN/ml
10¯⁶ - - - 0
10¯⁷ - - - 0

16. Questions
1. Is there any different in bacterial number for water sample
from tap water, stream and selected wastewater? What does
this indicate?
• Yes, there is a difference in bacterial number between these water
samples.
• Municipal tap water should be very low if not zero for harmful
bacteria.
• Stream water can be low or high depending on animal activity and
if there are any sewer facilities. They can be contaminated from
many different sources.
• Wastewater can mean two distinct things. It can be the water going
into the treatment plant or the treated water coming out of the
plant. Going in the bacteria level will be very high, in the millions
or more. Leaving the treatment plant will be low or zero.
• Bacteria levels indicate possible contamination and potential (not
absolute) harms to humans

17. 2. Why is it important to determine the number of coliform
bacteria in a water source?
• The total coliform test is the basic yardstick for
determining a water supply's biological quality.
• This test is performed frequently because of the risk that
disease-causing organisms pose to health.
• Any food or water sample in which this group of bacteria
is found has potentially come in contact with domestic
sewage, animal manure, or contaminated soil, plant, or
animal material.