Agenda - Council - 11/22/1994 - Laserfiche WebLink

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The mixed matcri~.ls will be loaded into thc ten concrete bays. Tc. mpcraturc and a.cration controls will maintain aerobic conditions and optimum temperatures during the composung process. A series of blowers//re mounted at intervals along thc side of' the outer bays. Each bay will have five independently con[ri'oiled aeration zones. Thc blowers arc conmolled by an automatic temperature feedback system,~s well as timers, for forced aeration. Thc airflow moves up from thc bottom of thc bays via a system of perforated pipes. Each blower is independently controlled allowing precise tcmpcratu~ management during thc cnm'c composting process. Automatic control of thc aeration blowers is obtained by means of thcrmocouplcs permanently mounted in the ba~, wails. Data is fed to a programmable micro-processor which tums the blowers on and off. Thiisystem also maintains and records temperature data for operation control purposes. Two IPS agitator~ will be used to process the material approximately once per day in each bay. Material will re~ain in the bays for approximately 17 to 21 days. Finished material will be removed once da~;y from each bay and stored outside on an asphalt paved area. The product storage area is size. to allow for six months of storage to enable the material to be stored through the winter months,~ The products stored outdoors will be arranged in a windrow fasb/on to prevent the material from ~oing anaerobic and generating bad odors. The odor from inside the building, generated from the composting process, will be exhausted from the building throt~gh an outdoor bio-filter. The exhaust air will be forced through the bio-filter odor control systetn which breaks down odorous compounds through adsorption, absorption, and microbial degrad~.tion. The bio-f'flter is composed of an aeration piping system laid in a stone plenum which is ~vered by approximately 3' 6" of bio-filter media and mulch cover. The bio- filter media is a mlxture of bark mulch, compost and wood chips. The building will be maintained under negative pressure using fans in order to control odorous air within the building. Operation of the fans will be controlled by building temperature and relative humidity. ~ The compost will,be marketed directly by IPS markenng d~v~mon. The primary end users are anticipated to be limdscapers, road contractors, nurseries, State and County highway departments, etc. Any excess p~oduct will be sold to Waste Management of Minnesota, Inc. (WMMI) to use for soil enhancement ~f land.f'2l borrow areas and soil enrichment of completed areas of the landffil. V~rMMI estimates ~hat it could use all of the compost produced by the IPS facitit3, for a minimum-of zl.5 years. An informational meeting was hosted by the applicants on November 30, 1993. Nearby residents of the proposed f~gcility, as well as the Ramsey City Council members, Planning and Zoning Commission merr~ers, County Board members and County staff were invited. At the meeting the following issues ~ere discussed: operation of the plant, types of waste materials accepted, the composring process, material produced, odor and noise control, vehicle traffic, etc. Following the presentations, the ~udience was given the opportunity to ask questions and voice their opinions and concerns regardin~ the facility. Minutes from this meeting are enclosed. On December 7, 1~}93, City Staff met with the applicants to discuss issues of concern. One of the issues discussed ~t~s the biofilter and what the back-up Would be in the event of equipment failure. We learned that tile biofilter is designed in such a way that no more than 1/2 of the system could fail at once. Going[ to 1/2 a system upon equipment failure would result in-something less than the normal 8 - 12 air {::hanges per hour inside the building, but the number of air changes would be enough to keep th~ worker comfortable. The entire bio-filter system can be replaced in just 2-3 days.