Infrastructure and Structural Engineering (Water/Wastewater Engineering): Milwaukee, WI

MMSD Private Infiltration and Inflow (I&I) Evaluation, Milwaukee, WI
IES_P6270469OTIE conducted a data collection and field investigation involving televising, electro-scanning, and lateral inspection for the MMSD Private Property Infiltration and Inflow (PPII) to reduce I/I that entered the sanitary sewer system. The results revealed that rain water entered the sanitary system through defective pipes. To repair these pipes and reduce backups, OTIE evaluated the data to determine the best course of action to minimize I/I.

To investigate pipe conditions, OTIE used Electro Scan technique which involved passing an electrical probe through a pipe filled with water. The probe emits electrical current which passes through the pipe wall into surrounding soil, ultimately to complete an electrical circuit with a ground rod. OTIE’s investigation services included the following activities:

  • Develop Electro Scan SOP and inspection documents to improve consistency, efficiency, and quality control for field and office work
  • Performed controlled test pit for QC comparisons
  • Developed a database, spreadsheets, and scatter charts to analyze data
  • Analyzed field data and assisted the project manager with developing techniques for comparing Electro Scan field results to CCTV, infiltration, and exfiltration data as well as duplicate tests, controlled tests, and test results from other projects
  • Provided input for the final Water Environment Research Foundation (WERF) report including charts, graphs, tables, duplicate test analysis, special case analysis, and project learning lessons

In addition to Electro Scan, OTIE supervised and conducted hydraulic loading (“soaker hose”) and storm sewer dye testing accompanied with sewer televising.

Client Name: MMSD


Location: Milwaukee, WI


Contract Value: $102K


Project Features:

  • Data collection and investigation
  • Electroscanning
  • Lateral inspection