08 Feb 2022

Utility case: Finding 5x more critical sewers with the same CCTV inspection effort

The ability to use existing CCTV inspections, together with GIS and contextual data to predict the structural or operational condition in the entire system makes it possible to direct the next inspections to the most critical assets at any moment, with speed, cost and efficiency gains – and a leap forward in renewal planning.

 

This utility promotes a CCTV inspection program of sewers and manholes as part of their effort to manage infiltration & inflow (I&I) and SSOs, recover system capacity and prioritize network renewal. 

Baseform’s Inspections Analysis module correlates CCTV inspections with GIS and other contextual data to predict the likely condition of uninspected sewers and manholes, or inspected at an earlier date. 

In particular, it provides a running list of assets prioritized for inspection or for action at given moments, and a framework for planning and optimization of CCTV inspections. 

 

The utility achieved a 60% reduction in CCTV annual cost without loss of efficiency in finding assets needing action (‘criticals’), directing and planning each new batch of inspections according to the software’s predictive capabilities. 

This utility uses PACP categories 4 and 5 as ‘critical’, i.e., triggering protocols for deferred or immediate action, respectively.

The average success rate in finding critical sewers was close to 6% (6 out of 100 sewers), working from an annual budget of nearly $2M to stay within the defined strategic target for locating critical assets and controlling I&I and system deterioration.

Baseform’s predictive capability (see figure above) increased that success rate to 34%: i.e., 1 in every 3 inspected sewers is a 4 or a 5. This enabled the utility to:

(i) fulfil their CCTV inspection target with a 60% cost reduction, or a savings of over $1.2M/year;

(ii) develop specific deterioration curves based on own data, with much improved reliability for O&|M and renewal planning;

(iii) revise the Asset Management plan to reflect the most recent deterioration curves and system- specific EUL (expected useful life) estimates.

Inspections prediction are further combined with Baseform’s failure event prediction to address SSOs, and the software’s flow monitoring and event detection to quantify I&I and home in on hotspots.

This 3-pronged approach leverages Baseform’s consolidated data platform where the diverse data sources are validated and reconciled, providing a consistent foundation for users across the utility.

UTILITY PROFILE

Population served: 936 250

# clients: 240 100

Total network length (water supply): 4,100 mi

Total network length (sewer system): 2,995 mi

Available data systems

• GIS; gravity sewer system, pressure system

• CCTV inspections: records used since 2006

• Maintenance/work orders: records used since 2008

Focus of Baseform implementation

• I&I management

• Proactive maintenance and CCTV inspection; planning/ optimization

• CIP planning (sewer system and WWTPs)

DATA LEVERAGED IN THIS CASE

Baseform’s software is designed to take full advantage of the data that already exists in the utility, depending on each application objective.

The software connects to the available data systems in an automated, non-intrusive and completely secure manner.

In the case of this specific utility and the application described here, data from the systems highlighted below were used.