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Private Property Infiltration & Inflow Reduction Program

The City of Franklin is one of the fastest growing communities in Wisconsin.  Since our incorporation in 1960, the population has more than tripled from 10,000 to over 35,000, and we envision it doubling again by 2035.  Franklin is also a full-service community, providing public sewer, water, and stormwater conveyance systems to all of our residents.  To make sure that we continue to provide the level of urban services that our residents are accustomed to, we monitor our systems on a regular basis to address potential issues before they become problems in an effort to save money, time, and resources for all of our residents.  To that end, the City of Franklin is working with the Milwaukee Metropolitan Sewerage District (MMSD) on a Priviate Property Infiltration and Inflow (PPII) Reduction Project in the area identified in Figure 1.  This project involves inspection of private property to better understand factors that contribute to sewer backups in the City of Franklin and are provided as a service by the City at no direct cost to the property owner.

Figure 1.  Map of the Project Area

PPII Program - Figure 1: Map of the Project Area

The PPII Program

The first part of the project is nearly complete and consists of monitoring the flow within the sanitary sewer system to see if the flow changes when it rains; Figure 1 shows the project area. The sanitary sewers carry sewage from your house to the wastewater treatment plant. Storm water should not be collected in the sanitary sewer system, but in the storm sewer system. If the flow in the sanitary sewers increases when it rains, then that indicates the presence of infiltration and inflow (I/I), which is stormwater and groundwater that enters the sanitary sewer system. If the flow increases beyond what the sanitary sewers can handle, then sanitary sewer overflows and basement backups can occur, creating damage such as shown in Photos 1 and 2.
Photo 1. Damage from a Basement Backup (Source:

Photo 1: Damage from a Basement Backup
Photo 2. Damage from a Basement Backup (Source:

Photo 2: Damage from a Basement Backup

The PPII program aims to reduce I/I that is specifically generated from private property. Reducing I/I from the sanitary sewers is important because the sanitary sewers are only designed to handle a certain amount of flow and, if more flow ends up in the sanitary sewers than was designed, sanitary sewer overflows and basement backups can occur. Typical sources of PPII are identified in Figure 2 and include defects or breaks in the lateral pipe, which is the pipe that takes the sewage from the house to the sanitary sewer system in the street. Other sources of PPII are improper connections of the storm system to the sanitary sewer system, such as:

  • Connected foundation drains
  • Connected downspouts
  • Connected sump pumps

Figure 2. Sources of PPII (Source

Figure 2: Sources of PPII

The Investigation Process

The City of Franklin is planning to conduct external and internal house investigations to try to identify sources of PPII. Investigations are voluntary and are intended to determine actions to be taken that could help homeowners keep their basements dry and prevent or reduce the frequency or severity of sewer backups. After receiving a signed right-of-entry waiver form from a homeowner, the investigation will include: 

  1. Visual observation of the house exterior to determine if there are drainage issues around the house exterior that are contributing to water entering the basement, and
  2. Visual observation of the house interior and exterior to identify if there are improper connections of the storm system to the sanitary system. 

If any drainage issues or improper connections are found, the City will explain the repair process, why the repair should be completed, and work with property owners to fix the issue. Immediate corrections will not be required.

In light of the social distancing requirements implemented by the State of Wisconsin during the COVID-19 pandemic, an option for either an in-person or a virtual interior investigation will be provided.  

  • For in-person interior investigations, two City representatives will enter the home where the resident will direct them to the basement. The representatives will then proceed to examine and document the plumbing fixtures.
  • For virtual investigations, a City representative will provide a tablet computer for the resident to use during the investigation and setup a video call between the representative and the resident. The resident will then bring the tablet into the basement where the representative will guide them through recording the layout of the plumbing fixtures and allowing for observation by the representative. The provided tablet will be disinfected before and after use. 

During all investigations, representatives will be wearing proper protective equipment (masks, gloves, safety glasses), disinfecting any surfaces they come in contact with, and maintaining 6 feet of distance between them and the resident, whenever possible. Investigations will be scheduled with each homeowner and will typically take 15 to 30 minutes to complete. In addition, the City and its contractor(s) may take photographs and/or videos of your property as part of the inspection.

Should you have any questions, please contact Glen Morrow at 414-425-7510 or via email.

How to Sign Up

If you own a house within the project area and want to sign up for the program, please complete and sign the Investigation Waiver Form and send it to:

PPII Program
Brown and Caldwell
Attn: Suzy Wood
250 E. Wisconsin Ave., Ste. 1600
Milwaukee, WI 53202

Or scan the waiver form and email it to Suzy Wood at Brown and Caldwell.  The letter must be postmarked or sent by email no later than October 5, 2020 for you to be eligible to participate in the program.

Letter to Homeowners from the City Engineer

For additional information on the PPII program, please check out MMSD’s website.

Engineering Department

9229 W. Loomis Road
Franklin, WI  53132

Phone:  414-425-7510
Fax:  414-425-3106

Hours:  M-F, 8 a.m. to 4:30 p.m.

Glen Morrow, P.E., City Engineer

Tyler Beinlich, P.E.,
Assistant City Engineer


Related Links

Board of Public Works
Board of Water Commissioners
Plan Commission