Rainfall Measurement
RJN will measure the contribution from rainfall to all sewersheds within the City’s jurisdictional boundary using a network of rain gauge stations with a minimum coverage of one (1) rain gauge station per ten (10) square miles as well as data compiled by Doppler radar utilizing a minimum resolution of one (1) pixel per four (4) square kilometers. To measure the contribution from rainfall occurring in portions of the Collection System outside Baltimore City limits, the Consultant shall install additional rain gauges outside City limits. The rain gauge equipment will be calibrated prior to installation, and shall consist of a data logger able to accept data from an industry standard rain tipping bucket. The equipment shall be able to measure 0.1 inches (1mm) per tip of bucket.

Groundwater Gauges
The Consultant will install groundwater gauges at 10% of the flow monitoring sites designated by the City. Each groundwater gauge will consist of a conduit (preferably a clear flexible tube) of sufficient diameter to accommodate a pressure sensor. The pressure sensor shall be calibrated prior to installation

GPS
Survey-grade GPS (Maryland State Plane - +/- 0.5 inch) coordinates, pipe inverts and rim elevations; and three (3) digital images of the site will be provided, including one showing the sensor installation.

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