An Overview of the New Subdivision Flow Monitoring to Assess Performance of Inflow and Infiltration (I/I) Prevention

All wastewater collection systems are designed to convey water to a designated point. They are meant to allow for a small amount of extraneous inflow and infiltration (I/I). But more often than not, there is higher I/I than anticipated and can present capacity issues to the sanitary sewers. That’s what makes new subdivision flow monitoring as well as inflow and infiltration inspections so important; it protects your subdivision by ensuring you have the appropriate capacity to manage the actual amount of I/I you’ll face, in addition to helping you meet relevant regulatory standards (where applicable).

Introduction to the New Subdivision I/I Prevention Program

Basement flooding, environmental spills, and sewers overloads can all be consequences of not being prepared for the level of inflow and infiltration you face. That’s why new subdivision I/I prevention is critical to efficient municipal wastewater management.

Increased I/I could be the result of:

• Cracked or broken sewer pipes
• Defective maintenance holes
• Improperly connected roof and foundation drains
• Submerged maintenance holes not adequately prepared for high-level wet-weather events

New subdivision flow monitoring, inflow and infiltration inspection, and general water flow monitoring systems will all be critical in subdivision I/I prevention.

New Subdivision I/I Prevention Process & Plan

The New Subdivision I/I Prevention Process and Plan is relatively new for many municipalities.  Plans typically establish guidelines and standards that help inform subdivision wastewater construction, testing, and inspection.

The Objective of New Subdivision I/I Prevention Programs

Among the more than 40 subdivisions that Civica has completed the flow monitoring portion of the plan, preliminary analysis has shown that more than 80% have demonstrated a conforming I/I response (e.g., less than 0.12 L/s/ha during a projected 25-year storm) and are on their way to complete the program. The results of the flow monitoring are a testament to the standards and guidelines for construction and monitoring that municipalities have put together to implement these programs. Continued modifications to the programs are expected in the near future to maximize the benefits and provide additional guidance for all parties involved.

While we still lack long-term data due to the relative newness of these programs, the early results are very positive in terms of I/I reduction. The new flow monitoring system requirements have proven—at least thus far—effective at substantial I/I reduction, indicating that the standards are likely here to stay.

While this does mean higher investment on the part of the developer, the efforts likely far outweigh the cost of dealing with major flood damage and other complications from I/I oversights.

Contact Civica to Learn More about the New Subdivision Flow Monitoring

Civica is a leader in municipal wastewater and stormwater management solutions. Our expertise spans across sanitary and storm sewer systems as well as natural watershed asset planning and asset management. We offer consulting on inflow and infiltration inspection services, flow monitoring, capacity assessments, collections systems consulting, and more.

Click here for more information about the New Subdivision I/I Prevention Program. Or contact us today for a free consultation.

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New Subdivision Flow Monitoring To Assess Performance of Inflow and Infiltration (I/I) Prevention