Dual Plumbing and the possibility of fecal – oral transmission of disease vectors including the COVID-19 virus. Need for an Audit
By Dr. Yashpal Singh, Chairman, The Wealthy Waste School India
The possibility of fecal – oral transmission of disease vectors including the COVID-19 virus has been sufficiently established. The MoEF & CC is recommending dual plumbing for water closets in the environmental clearances being issued by it. A need is being felt for an audit of the entire practice.
It has been scientifically established that flushing a toilet can generate a cloud of aerosol droplets that rise high and may carry pathogens which have detrimental health impacts. Viable virus particles have been found in patients feces as well as on toilet bowls and sinks in hospital and isolation rooms. A general solution to the problem is generally suggested as closing the lid during flushing. This however, in itself, appears to be a very unhygienic practice as the next user could be exposed to a cocktail of pathogens adhering to the inner lid and the seat. Fecal-oral transmission has been reported to be a common transmission channel for most viruses along with other pathogens.
The WHO has observed that Waste waters from toilets, urinals or bidets contain high level of pathogenic organisms and solids and should undergo specialized treatment prior to any secondary use. It has also advocated that extreme care is required to keep the two systems separate, to prevent cross connections and to prevent inadvertent use of non-potable water for food preparation or consumption by both humans and animals.
While the practice of flushing, in itself, is a potential factor in the spread of pathogens, the use of treated water for flushing increases the risk of contaminants, from ill managed treatment and plumbing systems, finding their ways in others toilets. This is a grave cause of concern. A particular stench and fouling of bidets have often been observed in toilets using treated water. Sometimes the same stench has been observed in water coming out of the attached faucets used for clean ups. The user is hardly aware of the quality of treated water or the pathogenicity of the water which is being used for recycle.
The Ministry of Environment, Forests and Climate Change, Government of India has been duly concerned of this issue since pre COVID days and has been taking care in advising that, in case of dual plumbing, the recycled water should not come into contact with humans. As a Member of the E.A.C. Infra-2, I remember having made recommendation to this effect while dealing with projects proposing dual plumbing. A need for an evaluation of the system was also felt. Currently the E.A.C. Infra II, MoEF&CC is recommending that the project proponents, “Would commission a third party study on the implementation of conditions related to quality and quantity of recycle and reuse of treated water, efficiency of treatment systems, quality of treated water being supplied for flushing (Specially the bacterial counts), comparative bacteriological studies from toilet seats using recycled treated waters and fresh waters for flushing, and quality of water being supplied through spray faucets attached to toilet seats”. The imposition of this conditions is deeply appreciated, but the study appears to be a post occupancy exercise with little corrective options and I wonder if, despite this condition, many such exercises have been undertaken or corrective actions taken.
Further the study may also suffer the defect of being a product of a third party hired by the project proponent. Once the occupancy is handed over, the project proponent may have little or no interest in the day to day running of the project,
The hopelessness generated by the present pandemic and the possibility of the virus to follow a fecal-oral route in transmission (through plumbing lines) may call for an audit and evaluation of the entire dual plumbing system which is being aggressively pursued in buildings across the country.
There appears to be a need of monitoring the compliance of this condition and to commission a study to audit some buildings where dual plumbing and use of treated waste water for horticulture or use in HVAC/Firefighting is practiced. The best agency to do this could be the CPCB.
It appears important to assess the pathogenicity of these waste waters and their impacts on health. It is also important to review the degree of treatment required for reuse of waste waters, the standards and the actual treatment achieved. Separate standards may have to be prescribed for treated waste waters to be used in dual plumbing, in horticulture and road side plantation, in HVAC and other alternative uses where there is a possibility of contact with humans. These would be ‘Use Standards’ and different from ‘Discharge Standards’.
The Ministry could be suggested to:
- Seek compliance reports from all project proponents to whom this condition of submission of a study report on dual plumbing has been prescribed through the Environmental Clearances/Consents granted by the Ministry/SEIAA/ Boards and Committees.
- Examine these reports and suggest a future plan for action.
- Consider formulating ‘Use’ standards, especially for pathogen management, for use of treated wastewater in dual plumbing, horticulture, HVAC, firefighting etc., where the effluents may have or may not have a possibility of human contact.
- Ask the CPCB, in association with some specialist institute, to carry out an audit on the use of treated waste waters for dual plumbing and other activities which may involve contact with humans. This could include an efficiency of treatment systems, quality of treated water being supplied for flushing and other uses, especially the bacterial counts, comparative bacteriological studies from toilet seats using recycled treated waters and fresh waters for flushing, and quality of water being supplied through spray faucets attached to toilet seats, the extent of the exposure and the impacts of this exposure on human health.
This does appear to be a very important issue requiring due consideration.