Plumbing Africa March 2023 | Page 39

HEALTH AND SANITATION 37

Therefore , the plumbing design professional has two incentives pushing them : ( 1 ) the avoidance of incurring risk on a project and having something go wrong and ( 2 ) finding the fastest way to complete the project . Both of these motivators mean that code is almost always followed closely . New concepts , materials , devices or innovations are generally not encouraged because they would both increase the risk to the engineer and take more time to implement due to the added time ( or cost ) for the engineer to research or develop the concept . Because of these factors , the MEP engineer , via their plumbing engineer , will default to just utilising Hunter ’ s Curve , as it has been adopted by codes for numerous years and streamlines the process of engineering plumbing systems . Unfortunately for plumbing systems ( and our health ), a lot has changed since 1940 .

Saving Water Reading through Dr . Hunter ’ s work ( BMS65 report ) from 1940 , toilets used about 4 gallons per flush ( gpf ). ( Remember that the toilet was the base unit used for the development of Hunter ’ s Curve .) For more than 40 years , 4 gpf for a toilet was the standard volume of water all plumbing and civil engineering utilised to size water and waste piping systems for buildings and municipalities . Sewer systems and sanitary and waste piping inside buildings were sized to accommodate these flow volumes .

Then , in the 1980s , there was an initial push to reduce flow rates of various plumbing fixtures . This effort was intended to help save water , but more in line to standardise plumbing fixture volumes .

Plumbing Africa Rory Macnamara sustainability and buildings that keep people healthy were the founding principles .

One of the specific environmental challenges that LEED v1 wanted to help solve was the usage of freshwater inside commercial buildings . In LEED v1 , the first initiatives aimed at further reducing the flow of water . Reducing water usage by volume further , subsequent LEED versions

Clean water disappearing maybe !

Residential Bathroom Lavatory Faucet

3.5 + gpm 2.5 gpm 2.2 gpm 2.2 gpm 1.2 gpm 66 %

Showerhead 3.5 + gpm 3.5 gpm 2.5 gpm 2.5 gpm 2.0 gpm 43 % Toilet – Residential 4.0 + gpf 3.5 gpf 1.6 gpf 1.6 gpf 1.28 gpf 74 %

Table 1.2

In August of 1998 , the Leadership in Energy and Environmental Design version 1 ( LEED V1 ) was released by the U . S . Green Building Council ( USGBC ). This was the culmination of five years of work led by senior scientist and environmentalist Robert K . Watson from Chicago , who spearheaded a consensus group of nonprofit organisations , government agencies , architects , engineers , developers , builders , product manufacturers and other industry leaders . Since then , the standard has undergone multiple revisions , with the latest , version 4.1 , being utilised at the time of this writing . USGBC stated the following with regard to the purpose of LEED : “ Our vision is that buildings and communities will regenerate and sustain the health and vitality of all life within a generation . Our mission is to transform the way buildings and communities are designed , built and operated , enabling an environmentally and socially responsible , healthy and prosperous environment that improves the quality of life .” A focus on energy continued to drive toward less and less water usage in buildings and was supplemented by the U . S . EPA ’ s WaterSense program in 2006 , which worked with LEED to reduce water flow rates further . These subsequent drives for less water usage have led to the advent of dual flush toilets ( 1.1 / 1.6 gallons per flush ), low flow toilets ( 1.28 gallons per flush ), waterless urinals ( 0 gallons per flush ), low-flow faucets ( 0.35 gallon per minute ), and low-flow showers ( 1.5 gallons per minute ).

Considering that we are seeing more and more water shortages across the United States , at first glance , most would celebrate this trend . From 1940 to 2020 , the water used by a toilet was reduced to less than 15 % of its original value — an almost 700 % decrease . While water conservation is of vital importance , especially in the water-starved Western United States , there are a number of unintended consequences that can occur from lowering flow rates without changing other practices . PA

March 2023 Volume 29 I Number 1 www . plumbingafrica . co . za