Memorandum

City of Lawrence

Utilities Department

MEMORANDUM

TO: David L. Corliss, City Manager

Cynthia Wagner, Assistant City Manager

Diane Stoddard, Assistant City Manager

FROM: Philip Ciesielski, Assistant Director of Utilities

CC: Dave Wagner, Director of Utilities

Charles Soules, Director of Public Works

Mike Lawless, Assistant Director of Utilities

Mark Thiel, Assistant Public Works Director

Steve Bennett, Building/Maintenance and Enginnering

Roger Zalneraitis, Economic Development Coordinator

Beth Frailey Krishtalka, Assistant to Director

DATE: October 27, 2010

RE: November 2, 2010 Agenda Item – Authorize Staff to direct BG Consultants to complete Bid Documents for Project UT0922CS, Airport Area Sanitary Sewer Improvements to include only the gravity collections system and septage holding well with aeration and odor control, and deferring construction of the forcemain.

Please include the following item on the City Commission agenda for consideration at the November 2, 2010 meeting:

Action Request. Authorize Staff to direct BG Consultants to complete Bid Documents for Project UT0922CS, Airport Area Sanitary Sewer Improvements to include only the gravity collections system and septage holding well with aeration and odor control, and deferring construction of the forcemain.

Project Background. The airport is located north of US Route 24/40 about one-half mile east of 3^rd Street. It is a valuable asset to the City, currently accommodating over 32,000 operations annually and generating over $9 million dollars in local revenue for the economy. The airport is approximately 500 acres, has two runways, a terminal, 36 t-hangars, and several small on-site aviation services and hangars used by local businesses and individuals. The airport is an “island” of City property, located about a mile north of the City border.

Airport facilities have no sewer services, using septic instead. County regulations prohibit more than one septic and lateral field every three acres. This requires land that could otherwise be used for development to remain as open space for septic.

There is an immediate need for additional sewer facilities at the airport. At least one septic system is failing, and some recent firm inquiries would require greater service capacity by late spring of 2010. Also, a number of business inquiries have occurred over the last year for locations at the airport that suggest that the airport has more demand for business space than can be accommodated by existing water and sewer service.

Project Description. The originally authorized project scope included the design of a gravity collections system on the airport property to a septage holding tank at HWY 24 with necessary telemetry and odor control, and a force main to existing gravity sewers in North Lawrence for future use when airport area flows necessitate the conversion of the septage holding tank to a lift station (see project map).

Project Status. The design team of BG Consultants and Burns & McDonnell have completed the plans and specifications for the gravity collection system and the septage holding well, and these components are ready to bid for construction. Topographic survey and design of the forcemain route have been completed, along with documentation related to required permanent and temporary easements.

Based on sanitary sewer capacity required by current airport facilities and the pending development requests related to DAR Corporation and Hawkeye, staff is recommending the current scope of project construction be reduced to only the gravity collection system on airport property and the septage holding tank at HWY 24. Water use records indicate the current monthly average use for the existing airport facilities will result in the need to only pump out of the septage holding well approximately once a month. The projected water uses for the proposed DAR Corporation and Hawkeye facilities would increase the pumping frequency to only twice a month. It is anticipated additional pumping may be necessary in advance of, and after, large events hosted at the airport. Based on these current and proposed capacity needs, and the generally reduced pace of development, the need to convert the septage holding basin to a lift station and utilize the proposed forcemain could be several years –if not a decade –into the future.

Buried infrastructure, even systems not in operation, are subjected to deterioration once constructed. In addition, after sitting dormant for potentially several years the forcemain would need to be pressure and leak tested as if new to verify its integrity. Typically this testing is completed on manageable lengths of pipe as construction progresses. With the work completed to date on design and easement requirements, the conversion of the septage holding tank to a lift station and the construction of the forcemain could be completed within the typical timeline for the siting and construction of a new industrial facility. Based on these factors staff is recommending removing the forcemain portion of the project from the construction to be bid. This reduced project scope accomplishes all of the current economic development objectives without over-building infrastructure for present and likely future needs.

City Staff have also discussed concerns raised by Douglas County Staff regarding the area of the forcemain portion of the project as an opportunity to extend sanitary sewer service to County residents south of I-70 and along E1500RD (map attached) currently on septic systems. In particular service to the rural subdivision at the intersection of N1732 RD and E1500 RD. The lots in this subdivision do not meet the current lot area requirement for the installation of new septic systems, and in the event their septic system fails they would not be permitted to construct a new system under rules governing unincorporated septic systems.

City Staff had previously and have again reviewed the concept to extend City gravity sewers north from North 7^th and North Street to the county residents. The extension of a gravity sewer north from North 7^th and North Street is feasible, would allow for a shorter forcemain and could be upsized to accommodate the future airport area forcemain flows. However, due to the flat topography of the area and depth of the existing gravity sewers any gravity extension north would be very limited in the area it could serve by further extension of the gravity lines to the residences. Preliminary analysis of service to the rural subdivision in at the intersection of N1732 RD and E1500 RD concludes that service to these residences would require either a small lift station or a system of individual grinder pumps to convey flow from the residences to a gravity line in North 7^th (E1500RD). The costs and operational issues associated with the additional pumping infrastructure - which will likely be considerable given the few properties to be served – has not been determined in detail. Under the City’s development policy, these costs have traditionally been solely borne by the property owner benefitting from the sewer improvement, unless the City or other parties have participated in the costs.

The overall development of a sanitary sewer service delivery plan for the unincorporated areas of Douglas County south of I70 would be most appropriately carried out during the master planning process. The City is currently under contract with Burns & McDonnell/BG Consultants for a Sanitary Sewer Master Plan. During the master plan activities potential future extensions of sanitary sewers into unincorporated areas of Douglas County will be planned. The layout of these extensions will be based on drainage basin wide service plans and provide the network from which service to discrete developments will extend. This process of drainage basin planning is similar to the planning and design of recently expanded sanitary sewer facilities in the Southeast Area.

To date there has not been a notification of failed septic systems, nor a request by the residents in this area to participate in the extension of gravity sanitary sewer service. By choosing to delay the construction of the forcemain there is the opportunity to receive the Sanitary Sewer Master Plan and incorporate its recommendations for service to this area into the future final design of the airport forcemain when or if it is eventually needed.

Provided the City Commission approves the requested scope and upon completion of the bid documents Staff will submit the plans and specifications to KDHE for approval and the issuance of a Sanitary Sewer Extension Permit. Upon receipt of the KDHE permit the project will be ready to bid for construction, and Staff will submit a City Commission agenda for consideration item setting a bid date.

Project Funding. Funding is via Public Works general obligation bonds for economic development.