Renovation of a water / sewer project in Des Moines, Iowa. Completed plans call for the renovation of a water / sewer project.

The base scope includes removal and replacement of deteriorated concrete at the cornice surrounding the elevated steel tank, rehabilitation of the existing historic railing at the cornice, installation of waterproofing membrane on the new cornice concrete, vertical and overhead concrete surface repairs, and cementitious parge coat repairs at the outer shaft wall. Alternate Bid 1 covers removal and replacement of discrete areas of concrete slab and steps at the base of the tower. Alternate Bid 2 covers vertical sealant installation at existing concrete cracks. All work must comply with the Secretary of the Interior's Standards for the Treatment of Historic Properties and guidance from the Iowa State Historic Preservation Office (SHPO). Existing materials should be retained whenever possible. Replacement and repairs of concrete elements with new material should occur only when the existing elements are so deteriorated as to prohibit their useful function, and with prior approval by the Engineer and Owner except as otherwise indicated in these documents. The work includes, but is not necessarily limited to: The Allen Hazen Water Tower was constructed in 1931 and is listed on the National Register of Historic Places (NRHP Ref# 04000819). The base scope of this project includes removal and replacement of deteriorated concrete at the cornice surrounding the elevated steel tank, rehabilitation of the existing historic railing at the cornice, installation of waterproofing membrane on the new cornice concrete, vertical and overhead concrete surface repairs, and cementitious parge coat repairs at the outer shaft wall. Alternate Bid 1 includes the lump sum work for removal and replacement of discrete areas of concrete slab and steps at the base of the tower. Alternate Bid 2 includes the lump sum work for vertical sealant installation at existing concrete cracks. All work shall comply with the Secretary of the Interior's Standards for the Treatment of Historic Properties, and guidance from the Iowa State Historic Preservation Office (SHPO). Existing materials should be retained whenever possible. Replacement and repairs of concrete elements with new material should be done only when the existing elements are so deteriorated as to prohibit their useful function, and with prior approval by the Engineer and Owner except as otherwise indicated in these documents. The estimated cost for the base bid is $810,900. The estimated cost for Alternate Bid 1 is $73,800. The estimated cost for Alternate Bid 2 is $43,400