4. Conclusions
Detection of wastewater in stormwater systems requires a
complex approach comprising comprehensive planning, preliminary
reconnaissance of sewer systems, development of a
detailed strategy, and execution of field measurements by
appropriate methods. The indicator parameters and methods
presented in this review all have the potential to detect stormwater
contamination by wastewater, under specific circumstances
and subject to limitations. The task of developing a
successful plan for a specific situation depends on the ability to
identify those conditions, which invoke those limitations, and
how they could be minimized. The best indication of wastewater
contamination is provided by human waste specific indicators,
i.e., chemical (e.g., caffeine and carbamazepine) and microbiological
markers (adopted in MST methods), whose field applications
require further development with respect to making them
fully operational and detecting intermittent episodes of
contamination. For municipal practice, the lack of inexpensively
applicable universal indicators points to the need to use combinations
of methods adjusted for specific cases. Several indicators
may reinforce each other, if one can minimize another's specific
limitations and uncertainties, or if one or another can bring new
and valuable information.
To develop the wastewater detection methodology further, it is
further suggested to undertake: (i) Comparative evaluations of the
current or newly proposed combined methods and strategies for
stormwater contamination detection, and (ii) further research on,
and development of, human waste specific markers (chemical and/
or microbiological) and their innovative sampling in stormwater
systems, including on-line monitoring and deployment of passive
sampling technology.