Memorandum

City of Lawrence

Department of Utilities                                                                                    

Date:  February 06, 2007

To:       Dave Corliss, City Manager

            Debbie Van Saun, Assistant City Manager

From:  Shelley Schupp, PE

            Project Engineer, Utilities Engineering Division

RE:      Residential Sanitary Sewer Service Connections Stub Out Detail

Beginning in 2001 The Board of Plumbers recommended that residential sanitary sewer service connection stub outs be installed concurrently with the public sanitary sewer main.  In 2003 The Board researched the other Big XII cities to determine their requirements for residential sanitary sewer service connection stub outs.  With the exception of the City of Columbia, Missouri, the other cities surveyed require residential sanitary sewer service connection stub outs to be installed as a part of the extension of the public sanitary sewer main.  Although the City of Columbia does not require the stub outs to be included with the sewer main extension, most public improvement plans submitted include them (as per Pat Fitzgerald, Supervising Engineer, City of Columbia).  In September 2005 The Board voted unanimously to proceed with the recommendation that the City require the installation of residential sanitary sewer service connection stub outs for every lot in new developments. The Board recommended using Lincoln, Nebraska’s existing standard detail for these stub outs as the basis for the City of Lawrence’s detail.   

Beginning in December of 2005 the Utilities Engineering Division reviewed the recommendation from the Board of Plumbers and has proposed to incorporate the attached residential sanitary sewer service connection stub out detail as a part of the City of Lawrence’s standard details of construction for sanitary sewers.  The Utilities Engineering Division has had the proposed detail reviewed and approved by the Kansas Department of Health and Environment.  The Division has made minor modifications to the standard detail from Lincoln, Nebraska, and proposed the following additional stub out requirements:    

- The station along the main and the horizontal length of the service connection stub out(s) for each lot shall be shown in the plan view of plan/profile sheets within the Public Improvement Plans.

- The service connection stub outs shall be constructed and tested concurrently with the public sanitary sewer main and inspected by the Department of Utilities.

- The service connection stub outs shall be shown on the as-built drawings generated by the Utilities Department (with corrected stationing and horizontal length, as necessary).

- The service connection stub outs shall be a part of the private sanitary sewer service line (see the notation on the detail distinguishing the city sewer main from the private service line). 

The advantages of the proposed change include:  reducing the depth of the excavation required to complete sanitary sewer service connections by the home builder/plumber; improving the quality of the service connection at the public main; and reducing potential inflow and infiltration.

On January 8 2007 Philip Ciesielski, Utilities Engineer, attended a Lawrence Home Builders Association breakfast function to discuss the implementation of the proposed detail.  Also on January 8, 2007 the Utilities Department summarized the proposed detail in a letter addressed to approximately 300 local plumbers, home builders, architects, contractors, developers, and engineers.  On January 17, 2007 a public meeting was held to provide further information, obtain feedback, and discuss the detail.  The meeting was lightly attended and the comments were positive but with minor suggestions concerning the recommended detail and its installation. 

Comments have been received from eleven companies, with only one company expressing opposition to the residential sanitary sewer service connection stub out detail.  The following companies responded positively, some with suggestions on modifying the detail:

- Bobbie Flory, Lawrence Home Builders Association (see attached letter)

- Charlie Mestagh, McLouth Excavating

- Dean Grob, Grob Engineering

- Chris Storm, Landplan Engineering

- Roger Johnson and Branden Boyd, RD Johnson Excavating

- Rod Hofer, Professional Engineering Consultants

- Aaron Gaspers, Peridian Group

- Michael Bader, Redford Construction

- Kent Earl, general contractor

- Kyle Buerman, All Star Plumbing

Based upon the suggestions received, the detail (attached) has been modified as follows:

- The service line minimum slope has been increased to 2 percent.

- The title of the detail has been modified to indicate that it applies to residential services.

- The maximum height of the fittings at the Tee on the public main has been reduced from 24 inches to 18 inches.

- The surface marker material has been modified from the steel t-post to a 1-inch diameter PVC pipe to prevent potential damage to the stub out.

Martin Moore, of Advanco, Inc, is opposed to the stub out detail requirement and his email is attached.   Advanco is also owned by Douglas Stephens and E.J. Allison.  I spoke with Martin Moore to review his concerns, however, he remains opposed to the sanitary sewer connection stub lines:

- The proposed change is wasteful.  The most efficient time to make the individual connections is during construction on the individual properties.  The plumbers providing comment have stated that the change will provide them a connection point that will minimize their required excavation and conflict with other utilities in the easement, and will allow them make the connection without tapping into a ‘live’ sanitary sewer main. 

- The location of the connection to the sanitary sewer main line might have to be moved due to the construction requirements on individual properties.  The sanitary sewer stub out is shown to be placed at the downstream corner of the lot to be served.  This location provides the most flexibility when constructing on the lot and connecting the service line.  The stub out locations may not be ideal if the lots are replatted after construction, but this is not the typical scenario. 

- The video inspections are working.  The video inspections are able to assess the taps made within a year of the construction of the sanitary sewer.  All taps made after this time, and their impact on the public main, are not inspected by video unless an event occurs that necessitates additional video or inspection.  The current practice of installing saddle taps has been a significant source of inflow/infiltration. 

- The sewer line connection may be abandoned, or prematurely damaged. The public sewer main is typically 8-10 feet deep, well below the other utilities in the easement with typical depths of 42-inch to 48-inch depth.  The service stub out will be extended at this deeper depth until it is 5 feet outside of the rear-yard utility easement, it rises to and is terminated 5 foot below grade.  For the typical development, this depth and layout will be adequate to avoid damage during the installation other utilities. 

The Department of Utilities will proceed with incorporating the residential sanitary sewer service connection stub outs into the City of Lawrence’s standard details of construction for sanitary sewers.  This subject will be included in the City Manager’s Report on the February 13, 2007 City Commission meeting agenda. 

Upon receipt and review by the City Commission, an updated letter will be sent to the original list of local plumbers, home builders, architects, contractors, developers, and engineers indicating the initiation of the new requirement.  Note that we are stating that all public improvement plans commenced after March 1, 2007 will require the inclusion of the residential sanitary sewer service connection stub out detail.