2.5.1. System-wide approaches
Pitt (2004) developed a practical system-wide strategy for
identifying illicit connections of wastewater source to storm
sewers, comprising two main parts: (1) Field screening and identification
of locations with obvious or highly probable wastewater
contamination; and, (2) planning and performing an advanced
chemical monitoring programme. In field screening, the Outfall
Reconnaissance Inventory (ORI) is first compiled using such
methods as visual and odour inspections, as well as simple field
measurements (e.g., by portable thermometers, or litmus indicator
papers, etc.). This step helps identify the priority locations, where
contamination is obviously present.
In the second step, an advanced monitoring programme is
performed using such indicator constituents as ammonia, boron,