Agenda - Public Works Committee - 04/19/2011

Home

Public Works Committee Date: 04/19/2011 By: Tim Himmer Engineering/Public Works Information Title: Consider Amendments to the City's Topsoil Ordinance Item #: 5. 5. Background: As a means of water conservation the City adopted a new topsoil ordinance on April28, 2009, which went into effect on June 8, 2009, and included the following: • The installation of a minimum of four (4) inches of topsoil over all exposed areas not improved with buildings and paving, excluding natural areas that are left undisturbed. • The topsoil requirement would apply to any lot, in any zoning district, being improved with the construction of a principal structure. • Topsoil is defined as "black dirt composed of unconsolidated material, largely undecomposed organic matter that is a suitable foundation for vegetative growth. The composition of the topsoil shall include a well balanced medium consisting of the following: • A maximum sand/silt content of 20% • A minimum organic content of 35% • A pH between 6 and 7 • Removal of all rocks in excess of 3/4" During adoption of this ordinance staff discussed an approach to pre -certify soil in an attempt to make the change easier for builders and contractors in locating the material, as well as for inspections and enforcement by City staff. Staff contacted several local suppliers and requested a sample of the material they market for potential inclusion on a list distributed to builders and contractors at the time a building permit is issued. Only one sample submitted would have met the newly adopted definition of topsoil; however that sample was submitted in the prior year when the ordinance was being investigated and was no longer available. Staff was concerned with the lack of suppliers and material that met the then current ordinance so this item was again discussed by the Public Works Committee on July 21, 2009. The direction from that meeting was to amend the topsoil definition within City Code to reduce the minimum organic content to twenty-five percent (25%), and increase the maximum allowable sand content to thirty percent (30%). The Planning Commission held a public hearing related to this proposed amendment on September 3, 2009. There were no persons in attendance to speak to this matter, but one letter in opposition to the amendment was accepted into the record and there was much discussion by the Commissioners. The biggest issues raised at that meeting were: • Whether the City should be participating in certifying the soil. • Whether the requirements were too restrictive and therefore caused a hardship for builders and developers (creation of a "Ramsey mix"). • Whether there were adequate sources of material available that would meet the City's specification. After much deliberation the Planning Commission motioned to approve the proposed changes. Following that meeting staff continued working toward implementation and discovered that the testing criteria used to certify the samples was slightly flawed. The problem that existed was that standard sampling and testing protocols for topsoil are conducted by weight, and all the previous discussions on this topic focused on a volumetric basis. This item was brought before the City Council on September 22, 2009 to introduce an ordinance amendment related to the definition of topsoil. Council did introduce the ordinance amendment that evening but requested that staff continue investigating options for improvement, with the understanding that water conservation was the ultimate goal.