1

(C-11) -WATER CONSERVATION REPORT (HCT)

Table of Contents

S. No. Title

Page Number

1. Details of water supply system

2

2. Figure 1. Diagram of SBR technology based grey

water treatment system

3

3. Figure 2. Diagram of SBR technology driven HCT

grey water treatment system

4

4. Detailed potable cold water budget

5

5. Detailed potable hot water budget

6

6. Detailed irrigation water budget

6

7. Sensitivity analysis

6

8. Drawings, schematic diagrams etc.

7

9. Contact information of the report authors

7

10. Water reuse treatment system

7

11. Result and Discussion

8

12. Microbial load in HCT Eco House grey water

8

13. ANOVA for HCT Eco House grey water

8

14. Post Hoc Analysis (Holm-Sidak method)

8

15. Table 1. Data for microbial load (CFU/100 ml) in

various water types

9

16. Table 2. One way ANOVA for comparing

microbial load (CFU/100 ml) in various water

types

9

2

17. Table 3. Post Hoc analysis (Holm-Sidak method)

for microbial load (CFU/100 ml) in various water

types

10

18. Figure 3. Vertical stacked graph for comparing

microbial load (CFU/100 ml)

11

19. Figure 4. Bar graph for comparing microbial load

(CFU/100 ml)

12

20. Figure 5. (Bacterial colony in Tap water/control

T0)

13

21. Figure 6. (Bacterial colony in Tank 1 with

aeration)

13

22. Figure 7. (Bacterial colony in Tank 2 with UV

treatment)

14

23. Figure 8. (Bacterial colony in Tank 3 storage tank

after UV treatment)

14

24. Contact information of the report authors

15

25. References

15-16

1. DETAILS OF WATER SUPPY SYSTEM: GRAF wastewater treatment system (Member of

German Water Partnership) with Manufacturing certified according to ISO 9001. SBR

Technology: Sequencing Batch reactors or SBRs use a separate pre-treatment section in the tank

to mechanically hold back solids (if any) and a biological aeration and settling tank (Fig 1). The

wastewater treatment system used for HCT eco house uses SBR technology (Fig 2). Treating grey

water with SBR technology is an advance treatment technology, where on a very small footprint

hygienically acceptable recycled grey water is produced effectively (Lamine et al., 2007).

3

Fig 1. Diagrammatic representation of SBR technology driven HCT wastewater treatment system

(Reference: http://www.graf-water.com/download/catalogues/wastewater-treatment.html)

4

Fig 2. Diagrammatic representation of SBR technology driven HCT wastewater treatment system

5

2. DETAILED POTABLE COLD WATER BUDGET: The details of potable cold water budget

required for the HCT eco house that is designed for 4 people.

Item wise Indoor water budget for ECO house at HCT.

Item Use Rate Flow rate No of persons

Total usage in

US gallons

Toilet

4.0 fluses per

person per day

1.6

4

25.6

Shower

4.8 minutes per

person per day

2.5

4

48

washing machine

0.30 loads per

person per day

40 gal per

load ( avg.) 448

Dishwasher

0.17 loads per

person per day 8.5 45.78

Faucet N/A 8.5

Baths

0.14 baths per

person per day

50 gal.per

bath ( avg) 4 28

Total 163.88 163.88

Toilet 25.6

Dishwasher 5.78

132.5 Gallons

Total grey water consumed for irrigation in litres per day 501.5125 Liters

927.5 Gallons

Note: with reference to both calculations, we have 501.2 liters of grey water per day for irrigation purpose.

esitmated quantity

Total grey water generated in Gallons per week

Remarks

one us gallon is equal to 3.785

liters

Total grey water consumed for irrigation in Gallons per day

water which is not usable ( sewer water)

6

3. DETAILED POTABLE HOT WATER BUDGET: The details of potable hot water budget

required for the HCT eco house that is designed for 4 people

Note: Potable hot water is included in shower water and dishwater.

4. DETAILED IRRIGATION WATER BUDGET: The detail information of irrigation water

budget is required for the HCT eco house.

5. SENSITIVITY ANALYSIS THAT EXPLORES THE UNCERTAINTY OF THE WATER

BUDGET AS A FUNCTION OF WEATHER VARIABLITY, OCCUPANT BEHAVIOUR.

APPLIANCE USAGE PATTERNS, SUPPLY PRESURE ETC.

Not Applicable (NA)

LA = GW/ET*PF*.62 after re-arranging GW= LA *ET*PF* 0.62 PF: Plant factor

LA = Land scape area GW: gallons per week ET: Evapotranspiration * ( inch per week)

PF is not available for specif trees and we used the maximum PF 1.2 for water balance.

ET = 2 in per week in california assumption California is hot and humid like Muscat

Land Scape area proposed by

HCT Team for different

plants/ grass etc

Land scape area

in sq feet Plant factor

GW for each

type ofplant

Total Water

demand in GW

area in Sq

meter

Morning glory, Petunia, and

Catharanthus roseus 167.8248 0.8

GW for each

type ofplant 166.4822016 15.6

Diffenbechia 42.70926 0.8

GW for each

type ofplant 42.36758592 3.97

Aloe vera 13.9854 0.7

GW for each

type ofplant 12.1393272 1.3

Khouta 244.42176 1

GW for each

type ofplant 303.0829824 22.72

Quisqualis Indica 41.9562 0.6

GW for each

type ofplant 31.2154128 3.9

Organic Vegetable** NA 1 NA NA NA 183 L/Year

Buffalo Grass 430.32 0.5

GW for each

type ofplant 266.7984 40

Date palm trees** ( 2 big and

4 small=6) existing.

Information : one tree

consuming 12 liters per day

in july which is maximum

water consumption NA NA NA NA 432 L/year

small 10 trees for barrier.

1liter per day per plant

GW for 10

green trees

for barries 18 Not defined

** NA : Not Applicable as grey water is not to be used for vegetable or fruit plants (as per the law)

Gallons available per week 927.5 840.08591Water balance per week =

(GW- Total surplus water) 87.4141

Balance of available grey water after being used for irrigation

http://www.fao.org

/docrep/006/y4360

e/y4360e0b.htm

for water balancing, gallons per week is considered, and we

have extra grey water for the existing plants, as per formula I

converted liter per day in gallons per week and we have extra

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6. IF DRWAINGS, SCHEMATIC DIAGRAMS, AND OTHER RELEVANT

INFORMATION ARE ALREADY INCLUDED IN THE DRAWINGS AND

DOCUMENTATION LIBRARY, IT IS NOT NECESSARY TO DUPLICATE THEM IN

THE WATER CONSERVATION REPORT. INSTEAD, PROVIDE CROSS

RERERENCES TO THESE OTHER DELIVERABLES.

(Please see the file ‘HCT-Greenest As built drawings as of 01312016)

7. PROVIDE CONTACT INFORMATION OF THE REPORT AUTHORS

(a) Dr. Pankaj Sah

Lecturer in Applied Biology

Applied Sciences Department

Higher College of Technology (HCT)

Al-Khuwair, PO Box 74; PC 133

Muscat (Sultanate of Oman)

(b) Dr. Kesaraju Seeta Ramchander Rao

Lecturer in Applied Biology

Applied Sciences Department

Higher College of Technology (HCT)

Al-Khuwair, PO Box 74; PC 133

Muscat (Sultanate of Oman)

8. WATER REUSE TREATMENT SYSTEM:

The reuse of domestic grey water has a significant role to play in sustainable urban future (Dixon et al.,

1999). It has been found that the grey water is the largest potential source of water conservation in

domestic residences, which contributes around 50 to 80% of total water use (Boal et al., 1996; Eriksson

et al., 2002; Jenssen and Vrale, 2003; Flowers, 2004; Al-Hamaiedeh and Bino, 2010). The pressure on

urban planning for sustaining ever-growing human population has initiated novel thoughts that can

potentially help in conserving precious water resources of the world.

The effluent produced by the installed treatment system has been subjected to test ‘microbial load’ in

HCT Applied Biology Laboratory. The results are as follow:

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Result and Discussion:

Microbial load in HCT Eco House grey water: Studies suggest that the micro-organisms can be

introduced into grey wastewater by hand washing after toilet use, washing of babies or small children

connected with diaper changes and diaper washing in bathrooms, as well as washing of uncooked

vegetables and raw meat in kitchen. The knowledge of introduction, survival and transformation of micro-

organisms in a grey wastewater system is a highly relevant issue to evaluate the efficacy of grey water

treatment system (Eriksson et al., 2002). The microbiological investigation of water is used worldwide to

monitor and control the water quality and safety of various types of water (Barrell et al., 2000). We

studied the microbial count in water following membrane filter technique with a pore size of 0.45 µm.

The membrane filter method is usually preferred over other methods for the detection of microbes in

water, this is especially the case where a few microorganisms are to be detected and enumerated in

relatively large volumes of liquid. The filter was taken out by using sterilized forceps and planted on

nutrient agar medium in a nutrient agar place in aseptic conditions. The inoculated nutrient agar plates

were place in an incubator at 37 0C for 48 hours in Applied Sciences Department project laboratory. The

bacterial colonies were counted by a colony counter for all the water samples (Fig 6 – 9). The experiment

was done in triplicates for all the water types.

The data was analyzed for comparative statistics e.g., mean ± standard error, One Way Analysis of

Variance (ANOVA), and t-test (two tailed). Values of P < 0.05 were considered as significant. All

statistical analyses were performed using Sigma Plot (Systat Software, San Jose, California USA)

The data and mean values were expressed in tabular form (Table 1).

Analysis of Variance (ANOVA) for HCT Eco House grey water: In order to understand the

effectiveness of grey water treatment system, we performed comparative statistics through one way

analysis of variance among all the grey water samples. ANOVA exhibited that there is a statistically

significant difference in ‘microbial load’ among the studied water samples (F = 20.123; df= 3; P < 0.001)

(Table 2). It was also found that the maximum microbial load (mean = 456.65 CFU/100 ml) was present

in ‘Tank 1 with aerated grey water’, and the minimum microbial load (mean = 60 CFU/100 ml) was

present in ‘Tank 3 i.e. post UV and storage tank for irrigating landscape plants (Fig 3 and 4; Fig 5 - 8).

This proves that the treated grey water from HCT eco house if very safe for landscape irrigation. Studies

have shown that WHO guidelines for treated waste water used for irrigation of agricultural crops and

public sports fields limit faecal coliforms to <1000/100 ml (World Health Organization, 1989). The

results show that the coliform bacteria are much lesser than the permissible limits of WHO guidelines for

HCT eco house treated grey water system.

Post Hoc Analysis (Holm-Sidak method) All Pairwise Multiple Comparison Procedures: We wanted

to explore the data further and to investigate the significant differences pair wise. For this pairwise

multiple comparison purpose we used post-hoc analysis with Holm-Sidak method. It was found that there

were statistically significant differences between all pairs of various water types (t value from 2.660 to

6.734; P value < 0.05 to < 0.001). However, there was no statistically significant difference found

between the pair of tap water (control) and tank 3 (final treated grey water (mean difference = 30

CFU/100 ml; t = 0.509; P = 0.620) Table 3. The results show that the grey water treatment system at

HCT eco house is treating the grey water very effectively and the final output water is safe for irrigating

landscape plants.

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Table 1. Data for microbial load (CFU/100 ml) in various water types for SBR based grey water

treatment system at HCT eco house

Type of Water Tap Water

(Tap Water/Control)

CFU/100 ml

Tank 1

(Aeration)

CFU/100

ml

Tank 2

(UV Treatment)

CFU/100 ml

Tank 3

(Post UV State)

CFU/100 ml

First replicate 150 470 230 80

Second replicate 60 270 380 70

Third replicate 60 630 290 30

Mean Value 90 456.6 300 60

One Way Analysis of Variance (ANOVA) Normality Test (Shapiro-Wilk) Passed (P = 0.053)

Table 2. One way ANOVA for comparing microbial load (CFU/100 ml) in various water types for

SBR based grey water treatment system at HCT eco house

Group Name N Missing Mean Std Dev SEM Replicates 4 4 -- -- -- Tap Water

(Control)

4 0 90.000 42.426 21.213

Tank 1

(Aeration)

4 0 456.650 147.271 73.636

Tank 2 (UV

Treatment)

4 0 300.000 61.644 30.822

Tank 3 (Post

UV State)

4 0 60.000 21.602 10.801

Source of

Variation

DF SS MS F P

Between

Groups

3 418902.667 139634.223 20.123 <0.001

Residual 12 83266.670 6938.889

Total 15 502169.337

The differences in the mean values among the treatment groups are greater than would be expected by

chance; there is a statistically significant difference (P = <0.001).

Power of performed test with alpha = 0.050: 1.000

One way ANOVA shows that there is a significant difference among the types of water (F =20.123; df =

3; P < 0.001). The results confirm that bacterial count was found to be highest in Tank 1 (with aeration)

mean = 456.666, followed by Tank 2 (UV) mean = 300 and Tank 3 (post UV and storage tank) mean = 60

CFU/100 ml. The microbial load in treated grey water is well below the guidelines set for International

standards.

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Post hoc analysis: All Pairwise Multiple Comparison Procedures (Holm-Sidak method):

Overall significance level = 0.05. Comparisons for factor:

Table 3. Post Hoc analysis (Holm-Sidak method) for pairwise multiple comparisons among various

water conditions in SBR based grey water treatment system at HCT eco house.

S. No. Comparison for microbial

load in CFU/100ml

Difference of

Means

t value P value P < 0.05*

1. Tank 1 (Aeration) vs. Tank

3 (Post UV State)

396.650 6.734 <0.001*** Yes

2. Tank 1 (Aeration) vs. Tap

Water (Control)

366.650 6.225 <0.001*** Yes

3. Tank 2 (UV Treatment) vs.

Tank 3 (Post UV State)

240.000 4.075 <0.01**

Yes

4. Tank 2 (UV Treatment) vs.

Tap Water (Control)

210.000 3.565 <0.01**

Yes

5. Tank 1 (Aeration) vs. Tank

2 (UV Treatment)

156.650 2.660 <0.05* Yes

6. Tap Water (Control) vs.

Tank 3 (Post UV State)

30.000 0.509 0.620 NO

(Not

Significant)

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Types of water at HCT eco house SBR based grey water treatment system

First Replicate Second ReplicateThird Replicate Mean Value

Mic

rob

ial l

oa

d in C

FU

/10

0 m

l

0

200

400

600

800

1000

1200

Tap Water (Control)

Tank 1 (Aeration)

Tank 2 (UV Treatment)

Tank 3 (Post UV State)

Figure 3. Vertical stacked graph showing detailed comparisons of microbial load (CFU/100 ml) with

triplicates in various water types for SBR based grey water treatment system at HCT eco house

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Types of water

Tap W

ate

r

Tank 1

(A

era

tion)

Tank 2

(U

V T

reatm

ent)

Tank 3

(P

ost

UV

Sta

te)

Ba

cte

ria

l Lo

ad

(C

FU

/10

0 m

l)

0

100

200

300

400

500

Mean Bacterial load

ANOVADF = 3; F = 20.123; P < 0.001

Figure 4. Bar graph showing comparison of microbial load (CFU/100 ml) in various water types for SBR

based grey water treatment system at HCT eco house

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Figure 5. (Bacterial colony in Tap water/control T0)

Figure 6. (Bacterial colony in Tank 1 with aeration)

14

Figure 7. (Bacterial colony in Tank 2 with UV treatment)

Figure 8. (Bacterial colony in Tank 3 storage tank after UV treatment)

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9. CONTACT INFORMATION OF THE REPORT AUTHORS: The contact information of the

report authors is as follow:

(c) Dr. Pankaj Sah

Lecturer in Applied Biology

Applied Sciences Department

Higher College of Technology (HCT)

Al-Khuwair, PO Box 74; PC 133

Muscat (Sultanate of Oman)

(d) Dr. Kesaraju Seeta Ramchander Rao

Lecturer in Applied Biology

Applied Sciences Department

Higher College of Technology (HCT)

Al-Khuwair, PO Box 74; PC 133

Muscat (Sultanate of Oman)

References:

1. Lamine, M., Bousselmi, L., Ghrabi, A. (2007). Biological treatment of grey water using

sequencing batch reactor. Desalination, Vol. 215, pp. 127-132.

https://www.researchgate.net/profile/Mona_Lamine/publication/234037338_Biological_treatment

_of_grey_water_using_sequencing_batch_reactor/links/0fcfd50e71f565d8db000000.pdf

2. http://www.graf-water.com/download/catalogues/wastewater-treatment.html

3.

4. Eriksson, E., Auffarth, K., Henze, M., Ledin, A. (2002). Characteristics of grey wastewater.

Urban Water, Vol. 4, pp. 85-104.

https://www.researchgate.net/profile/Mogens_Henze/publication/257587685_Characteristics_of_

grey_wastewater/links/0a85e52dd93473e947000000.pdf

5. Dixon, A., Butler, D., and Fewkes, A. (1999). Water saving potential of domestic water reuse

systems using grey water and rain water in combination. Wat. Sci. Tech. Vol. 39, No. 5, pp. 25-

32.

6. Boal, D.C., Evans, R.E., McFarlane, S. (1996). An investigation into greywater reuse

for urban residential properties, Desalination, Vol. 106, pp. 391–397.

7. Barrell, R.A.E., Hunter, P.R., Nichols, G. (2000). Microbiological standards for water and their

relationship to health risk. Communicable Disease and Public Health. Vol. 3, pp. 8-13.

8. Eriksson, E., Auffarth, K., Henze, M., Ledin, A. (2002). Characteristics of grey wastewater,

Urban Water, Vol. 4, pp. 85–104.

9. Jenssen, P.J., Vrale, L. (2003). Greywater Treatment in Combined Bio-filter/Constructed

Wetlands in Cold Climate, (Invited Lecture) 2nd International Symposium on Ecological

Sanitation, IWA.

10. Flowers, B. (2004). Domestic water conservation: greywater, rainwater, and other

innovations. http://beta.csa.com/hottopics/water/overview.php.

16

11. Al-Hamaiedeh, H., and Bino, M. (2010). Effect of treated grey water reuse in irrigation on soil

and plants. Desalination, Vol. 256, pp. 115-119.

12. World Health Organization (1989). Health guidelines for the use of wastewater in agriculture and

aquaculture. Technical Report Series 778, ISSN 0512-3054.