Page 75 - GRIHA Manual Volume IV - Introduction to National Rating System
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66 Griha Manual: Volume 4
21.2 Compliance
The following documents are to be submitted
21.2.1 Narrative along with drawings and specifications of the type of wastewater treatment
and harvesting system being employed.
21.2.2 Drawings indicating the specifications of dual plumbing system.
21.2.3 Document indicating the projected quality of water as per specifications.
21.2.4 Drawings with specifications of the systems, along with delivery lines, indicating the
capacity of wastewater treated and harvested.
21.2.5 Calculation sheet representing the total quantity of wastewater treated and harvested
and the amount being used for different applications including use within the building,
landscape, and fraction recharged into the ground.
21.2.6 Details of filtration system to allow that adequate preventive measures are being taken
to avoid contamination of aquifer by the recharged water (mandatory).
21.3 Appraisal (maximum points-5)
21.3.1 Annual water reuse of 25% as per clause 21.2.4 (1 point).
21.3.2 Annual water reuse of 50% as per clause 21.2.4 (1 point).
21.3.3 Annual water reuse of 75% as per clause 21.2.4 (1 point).
21.3.4 Recharge of surplus rainwater into aquifer (2 points).
Non-applicability condition
The irst three appraisal points shall not apply to projects that have wastewater generation on site less than 10 kL/day. The fourth
and ifth appraisal points shall not apply to projects in which the groundwater table is high and recharge of rainwater into the ground
is not advisable as per the Central Ground Water Board (CGWB) norms.
Water reuse is applicable only if provision for on-site wastewater treatment is technically and inancially feasible. As explained
in the earlier criterion, site generating less than 10 kL per day of wastewater may not necessarily opt for treatment of the
wastewater. Subsequently, in absence of any treatment there are no alternatives for wastewater reuse (not even for irrigation due
to health hazards). Therefore, 21.3.1, 21.33.2, and 21.3.3 are not applicable to such sites.
Subsequent appraisal 21.3.4 is subject to site-speciic conditions. Sites having high water table are liable to looding if provided
with water recharging facility. Similarly, sites which sit, on hard rocks or have clayey soil (such soils have very low iniltration of
water) cannot take rainwater for recharging. Refer to guidelines given by the CGWB in the Manual on Artiicial Recharge of Ground
Water for better understanding of non-applicability conditions. Thus, based on the hydro-geological conditions, groundwater
level, and other constraints, it may not be feasible to recharge rainwater in certain sites. Therefore, such sites shall fall under the
category of non-applicability condition.
Methodology
The steps to be followed to achieve the desired objective under this criterion have been presented
in the following diagram.
Step 1 Based on the building type and number of occupants, estimate the consumption of
water for different uses, that is, WCs/urinals, bathing, laundry, kitchen, external washing,
landscaping, and so on.
Step 2 Calculate the estimated quantity of blackwater and greywater generated from the building.
Step 3 Based on the reuse application and quantity of water required, select an appropriate
wastewater/greywater treatment system.
Step 4 Find out the water supply sources, scarcity and dry days if relevant. Calculate the rainwater
harvesting potential from the site and rooftop separately.
Step 5 Based on reuse application and site conditions, select appropriate rainwater storage and/or
recharging system.
21.2 Compliance
The following documents are to be submitted
21.2.1 Narrative along with drawings and specifications of the type of wastewater treatment
and harvesting system being employed.
21.2.2 Drawings indicating the specifications of dual plumbing system.
21.2.3 Document indicating the projected quality of water as per specifications.
21.2.4 Drawings with specifications of the systems, along with delivery lines, indicating the
capacity of wastewater treated and harvested.
21.2.5 Calculation sheet representing the total quantity of wastewater treated and harvested
and the amount being used for different applications including use within the building,
landscape, and fraction recharged into the ground.
21.2.6 Details of filtration system to allow that adequate preventive measures are being taken
to avoid contamination of aquifer by the recharged water (mandatory).
21.3 Appraisal (maximum points-5)
21.3.1 Annual water reuse of 25% as per clause 21.2.4 (1 point).
21.3.2 Annual water reuse of 50% as per clause 21.2.4 (1 point).
21.3.3 Annual water reuse of 75% as per clause 21.2.4 (1 point).
21.3.4 Recharge of surplus rainwater into aquifer (2 points).
Non-applicability condition
The irst three appraisal points shall not apply to projects that have wastewater generation on site less than 10 kL/day. The fourth
and ifth appraisal points shall not apply to projects in which the groundwater table is high and recharge of rainwater into the ground
is not advisable as per the Central Ground Water Board (CGWB) norms.
Water reuse is applicable only if provision for on-site wastewater treatment is technically and inancially feasible. As explained
in the earlier criterion, site generating less than 10 kL per day of wastewater may not necessarily opt for treatment of the
wastewater. Subsequently, in absence of any treatment there are no alternatives for wastewater reuse (not even for irrigation due
to health hazards). Therefore, 21.3.1, 21.33.2, and 21.3.3 are not applicable to such sites.
Subsequent appraisal 21.3.4 is subject to site-speciic conditions. Sites having high water table are liable to looding if provided
with water recharging facility. Similarly, sites which sit, on hard rocks or have clayey soil (such soils have very low iniltration of
water) cannot take rainwater for recharging. Refer to guidelines given by the CGWB in the Manual on Artiicial Recharge of Ground
Water for better understanding of non-applicability conditions. Thus, based on the hydro-geological conditions, groundwater
level, and other constraints, it may not be feasible to recharge rainwater in certain sites. Therefore, such sites shall fall under the
category of non-applicability condition.
Methodology
The steps to be followed to achieve the desired objective under this criterion have been presented
in the following diagram.
Step 1 Based on the building type and number of occupants, estimate the consumption of
water for different uses, that is, WCs/urinals, bathing, laundry, kitchen, external washing,
landscaping, and so on.
Step 2 Calculate the estimated quantity of blackwater and greywater generated from the building.
Step 3 Based on the reuse application and quantity of water required, select an appropriate
wastewater/greywater treatment system.
Step 4 Find out the water supply sources, scarcity and dry days if relevant. Calculate the rainwater
harvesting potential from the site and rooftop separately.
Step 5 Based on reuse application and site conditions, select appropriate rainwater storage and/or
recharging system.
