Kuhn argued that scientists become aware of anomalies in the paradigms they are working within when there is a recognition by scientists that "nature has somehow violated the paradigm-induced expectations". However, contradictions between theory and reality are not sufficient to dislodge an engineering paradigm where contradictions between theory and reality are not being constantly tested and a 'good enough' result is all that is required. An engineering paradigm is are not based on a best fit with nature but is socially negotiated. The interested parties must agree about its disutility.

Constant identifies one potential anomaly situation as "functional-failure" when the technology does not work very well because conditions have changed, allied technologies have changed or other parts of the system have advanced more quickly. The trouble with sewerage engineering is that such a failure is not clear-cut. There are certainly a number of people who would argue that conventional sewage treatment has failed to eliminate the problems associated with industrial waste and that the new fields of virology and ecology have pointed to important factors that have previously been ignored by sewerage engineers. However many engineers dispute this. They cope with changed situations as best they can by upgrading existing treatment plants, moving points of discharge and adding further stages of treatment to the paradigm. The weight of huge capital intensive technological infrastructures makes this the cheapest thing to do, at least in the short term.

Wojick argued that anomalies occur in technological paradigms when standard procedures repeatedly "fail to eliminate known ills" or when knowledge shows up the importance of factors which have previously been incorrectly evaluated. Those contesting the evaluation policy may be outside the paradigm community and their view may be disputed. They can then, Wojick says, turn to the government for a ruling. Those contesting the sewerage paradigm are indeed outsiders but this means that they are almost powerless to change it and their appeals to government have been ineffectual.

The government regulatory authorities are unlikely to force changes on the engineering community because they are well aware of the costs that would be involved in changing the system and the problems created by toxic chemicals and viruses are hard to prove, invisible, and their effects longterm. Most regulatory authorities employ and are advised by engineers who inform them of what is possible to achieve and what is not. They act within those bounds. Governments themselves can do no more than legislate that "the best practicable technology" is installed; they will not set standards that cannot be met by the available technology.

Public pressure and the cost (both economic and environmental) of new dams are beginning to force governments, such as the NSW government in Australia, to require engineers to at least explore the potential of treatment options which reuse and recycle wastewater as much as possible. Most recently, after years of dismissing the recycling of Sydney sewage as not feasible, Sydney Water announced that it would be beginning trials of water recycling facilities in a move to eliminate the need to build more dams and it has declared an "ultimate aim of stopping all dry-weather sewage discharges, either into inland waterways or the ocean through the city's coastal deepwater outfalls". In Israel, reuse of waste water has become the rule rather than the exception and this is likely to be the trend as clean water becomes scarce in various parts of the world.

Outside the engineering community, ecologists are working on various forms of ecological engineering which focus on the utilization and recycling of sewage. Niemczynowicz gives examples of Free Water Surface Systems, mainly consisting of oxidation ponds, and Subsurface Flow Systems, mainly consisting of wetland systems, both natural and artificial. He points out that such wastewater treatment systems are currently being researched in thousands of facilities around the world. Indeed ecological engineering is a growing field of study in itself with its own journal and text books.

For these new developments to be incorporated into normal engineering practice there needs to be a change in the sewerage engineering paradigm; in particular the emphasis on 'good enough' solutions at a minimum cost. 'Good enough' solutions have been defined by legislation which is shaped by the technological paradigm in place. In the past engineers have taken a certain pride in achieving minimum designs that comply with legislation. The philosophy of 'good enough' solutions at a minimum cost, needs to be replaced by one where engineers take pride in producing environmentally beneficial solutions that go beyond the legal standards that define 'good enough'.

The old paradigm has served the sewerage engineering profession well for decades but the profession is now facing a period of turmoil as debates rage over the appropriateness of the treatment methods available within the paradigm. Alternative treatments that do not fit easily into the primary, secondary, tertiary trichotomy are emergimg to meet new needs. Whether a technological revolution will emerge that will see a new paradigm put in place has yet to be seen.