Innovate building installations, but also assess the impact on the whole system

The (collective) drinking water installation connects the drinking water distribution network with the end-user, just as the building sewer system connects the municipal sewer system network with the end-user. Drinking water installations in homes, offices, hotels and hospitals provide people with water for consumption, showering, toilet flushing and more. Traditionally, a building’s drinking water installation and sewer system have been the domain of the plumber. Over the course of time, through trial and error and the introduction of a number of safety considerations, design guidelines and standards have been developed for these building installations. The design guidelines need most of all to ensure the required comfort: sufficient pressure, enough hot water, no ticking pipes and no odour nuisance. These requirements are usually met through the use of large-diameter pipes and bigger water heaters. These (overly) large dimensions have their downsides: they require more material, space and energy, and even have potentially negative impacts on health, though this has never been adequately researched. However, the biggest problem is that hardly any assessment has been made of the impact of the changes in an installation’s design or use on the water system as a whole, from the drinking water network up to and including the sewer network.

Innovations in building installations

To be sure, the installation sector has certainly seen improvements (let’s call them innovations). An installation in a 1920 home is not the same as one in a 2020 home. Lead pipes are no longer installed because of public health considerations; and the cost of materials and installation are limited through the use of plastic pipes with compression fittings, instead of soldered copper pipes. However, even though the average family size is dropping, and more water-efficient toilets, showers and washing machines are increasingly available, the design methodology for indoor installations has not noticeably changed. There are grounds to suspect that there is certainly room for improvement in this regard, for example, by achieving a better balance between comfort, (energy) costs and quality.

Assessment of the impact on the system is lacking

More and more innovations are coming onto the market: from new materials, heat recovery from shower water, to toilets that are flushed by a combination of compressed air and only 1.5 litres of water, point-of-use equipment for softening or filtration, and methods of quickly detecting leakages. But the development and market uptake of these innovations is never accompanied by an assessment of their impact on the water system as a whole. And yet, this is important: whenever something is changed in a building’s drinking water installation, this can have consequences for the provision of drinking water and/or the discharge of wastewater, and on the technical systems responsible for these functions. First of all, there is a lack of awareness that such a system assessment is necessary. And, secondly, there is no assessment framework available, nor is it immediately clear who would be capable of conducting such an assessment. And, lastly: it is also not obvious who should pay for an assessment of this kind.

Relevant

Nonetheless, such assessments are highly relevant. An example. A supplier of a toilet that uses compressed air for flushing has no clue about what the use of such a toilet means for the building’s sewer system, or for the sewer system in the street. True, a few field tests are being run on the campus of an English university, which involve an occasional check to see whether any clogging occurs in a number of manholes. But this does not provide a complete understanding of the effects on the system. In any event, if this pilot in the UK succeeds, this would not automatically imply that no problems would be encountered in the Netherlands. The design guidelines are actually set on a national basis: in each country, for instance, the ventilation structure is connected differently and the required slope varies.

Another example. Meter boxes and the pipe ducts are becoming increasingly crowded. Nobody has ever examined what impact this might have, for example, on drinking water quality.

Who will assess the innovations?

Drinking water utilities have a legal mandate to deliver drinking water to the meter box. The building installation is therefore not part of their operating area. Nevertheless, in the past they have also conducted research on indoor installations, even though the inspection of these installations falls outside of their legal responsibilities; in any case, the subject has disappeared from their research programme. The question now is: Who will take care of research and innovation in the area of building installations? Most companies in the installation sector are too small to bear the costs of elaborating an innovative idea to the point that it is guaranteed to work in practice as well. Look at the above example of the compressed-air toilet. Moreover, the system of advisors and installers as sub-contractors in projects results primarily in risk-aversive behaviour, rather than innovation incitement. The installation sector, through its branch association, Techniek Nederland, and the TVVL association, could put more money aside to stimulate innovation, but drinking water utilities and municipalities could also play a part here. Because innovations are clearly needed: resources are becoming scarce, so that limiting water, energy and materials consumption, as well as recovering resources, is becoming increasingly important. I believe we have to work together in finding a good solution to this problem in the years ahead.