Darwin Region Sewer Catchment Monitoring and Infiltration and Inflow Analysis

⁠⁠⁠GENERAL

• Supply and temporary installation of sewer flow meter and associated rain gauges at a number of sites within the Greater Darwin gravity sewer networks as specified in the schedule of flow meters within this RFQ.
• Data capture and validation at each site, including regular monitoring to minimize risk of zero or low quality data periods.
• Analysis and verification of data, including a report summarizing sewer incidents to wet weather events, peak flows, minimum flows, and derived flow patterns.
• Specialist analysis specifically for the Leanyer-Sanderson catchment including full Infiltration/inflow assessment and reporting.
• Supply of the validated sewer flow and rain data in electronic format (MS-Excel) to be utilized for future PWC model calibration and planning validation.
• There shall be no provision for sub-contracting under this contract.


BACKGROUND

PWC is undertaking an improved monitoring and analysis program of its gravity sewer networks in order to better inform the need and scheduling for capital expenditure and network augmentations.
This program will specifically target the Leanyer-Sanderson Catchment for the purposes of specialist Inflow and Infiltration analysis. This analysis will be used to target I&I reduction expenditure to where it is most required, and potentially as a validation for dilution rates used in PWC modelling and planning.

Due to synergies in the deployment of these temporary gauges, opportunity for further future uses, and in order to provide confidence and uniformity in data collection across multiple catchments for validation purposes; this program will also include flow meters installed across other catchments however only at key hydraulic monitoring locations (i.e. a smaller number of the same meters installed that will allow for system flow balancing and model calibration with data continually checked and validated by the specialist consultant; however not a large enough number of meters expected to be sufficient for detailed I&I analysis).

SCOPE REQUIREMENTS

This project seeks a Gravity Sewer monitoring and Inflow & Infiltration specialist to:
• Provide detailed monitoring in the Leanyer-Sanderson catchment sufficient enough to undertake a detailed I&I analysis
• Provide a detailed I&I report for the Leanyer-Sanderson catchment
• Provide a sufficient level of gravity network monitoring across the Ludmilla, Berrimah, and Palmerston sewer catchments capturing wet and dry weather flows from which base flows and flow patterns can be reasonably derived/inferred
• Utilize the latest technology with streamlined meters measuring velocity, depth, and pressure so as to capture both partial and full (including surcharged) pipe flow
• Provide reliable and accurate meter data
• Provide data at a high enough resolution to capture upstream pump flow events


DELIVERABLES

• Infiltration and Inflow report for Leanyer-Sanderson Catchment
• Copies of flow and rainfall data for all specified locations across Greater Darwin provided in electronic format (MS Excel or similar). This includes fortnightly raw and preliminary validated data for all flow and rainfall gauges
• Summary assessment for data at locations not within Leanyer-Sanderson I&I catchment area.