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Fall
1998 Newsletter
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Contents YOUR COMMUNITY'S VIEW OF INFRASTRUCTURE NEEDS |
Your Community's View of
Infrastructure Needs by Glenn D. Cooley, PE A Spring 1998 survey of Western New York government officials was recently conducted to determine their opinions on infrastructure issues. Most persons completing the survey represented Towns followed by Villages and then Counties. Sixty percent of the officials came from municipalities of a population of 1000 to 3000, forty percent from those with populations greater than 3000 persons. The respondents to the survey answered the questions on the urgency of their infrastructure needs in the five categories below: Percent Responding (most urgent) (least urgent) 1 2 3 4 Streets/Parks 10 50 20 20 Water Facilities 30 50 10 10 Sewage Facilities 20 60 10 10 Parks & Recreation 10 50 40 00 Community Building 20 20 40 20 For past projects these communities have been able to get grants or loans in 50% of the cases. However, 80% of the people indicated that they would not be able to do more infrastructure work without grants or low interest loans. E&M is available to assist you in ways beyond typical design services. You don't need a big project or a detailed design contract to use our services. The following is a list of some of the non-traditional services we can provide:
Green Areas, Wetlands & Wastewater Coexist by Jeffrey C. Bahret, PE Any type of development today, be it residential subdivision or commercial/ industrial plaza, requires the site planning engineer to derive more resourceful ways of satisfying the requirements of a multitude of involved agencies. The developer's goal is nearly always the same, that being to maximize the land area which is revenue generating within his finite parcel. Although, the subjects of green areas, wetlands and wastewater are recognized as very important necessary components of any project, they have the effect of being diametrically opposed to the developer's primary goal. Although the site planning engineer can do little to reduce the size of any one particular classification; he can, through careful development, reduce the total combined area required by creating multiple purpose zones. Let's say a developer wants to create a residential subdivision of a 50-acre parcel. The following conditions exist: * The municipal local zoning ordinance for residential subdivisions requires a minimum of 20 percent of the total parcel area be segregated out as common green area. *The site was surveyed and a five (5) acre area was found to have hydric soil types along with vegetation, which identifies it as a freshwater wetland. * The development is in an area where no public sanitary sewer facilities are available; and, therefore, on-site treatment and disposal of all wastewater must be provided. *The NYSDEC will require an advanced "tertiary" level of treatment before discharge to the on site intermittent tributary stream. Taking these conditions at face value, the loss in development area is 10 acres for the green area, 5 acres for the potential freshwater wetlands and a minimum of 2 acres for the tertiary sand filters needed for final wastewater polishing. Here's the alternative; combine all three types of non-capital return parcels to fit within the largest entity, that being the 10 acre green area. The combined multiple purpose zone method is dependent on creating a new manmade wetland. The new manmade wetland (5 acre minimum) would be constructed within the designated common green area and would allow for standard residential lot development within the originally identified potential wetland area. Studies have shown that wetlands have an affinity for certain pollutants in wastewater. The bacteria and plants in wetlands are generally starving for phosphorus and nitrogen which the wastewater provides. The raw sanitary wastewater would require primary treatment and some aeration before discharge to the wetlands. The water coming out of the wetlands will be very clean, exceeding the level of advanced tertiary treatment required by the environmental regulatory agency. A controlled manmade wetland is a very dependable natural system that costs very little compared to advanced water treatment. In this example, we were able to regain 14 percent of the total development area for capital revenue benefit. Demolitionby Allan R. Vanderpoel, PE Before you build, it is often necessary to clear a site so that construction can start without the existing developments impending progress. Occasionally the site contains a structure which needs to be demolished. While it sounds like a simple affair to have a bulldozer come in and push the structure into a pile of debris, often there is more to consider than this direct approach. The first concern is if the structure contains any hazardous or other materials that require special attention. An environmental assessment may need to be done so a professional can determine if asbestos, lead, radon, PCB's, formaldehyde, or underground storage tanks are present, as well as a host of other items. These materials will have to be properly removed and disposed of, in most cases before the structure is taken down. Of equal concern is the protection of adjacent improvements from damage during demolition. While it is not necessary to provide exact details of the demolition work in order to protect a neighbor, it is prudent to point out nearby improvements and state a penalty in case damage occurs. It is essential that any improvements on the parcel itself which are to remain be noted for protection. Removal of the site material is the next concern. It needs to be pointed out if the owner wants to retain any salvaged items, or if all material is to be removed. If any material can be buried or burned on site (although this is usually not acceptable) the cost of demolition will be less. Items which need to be transported to a landfill, or others that can be used as off-site fill need to be specified. The way to keeps costs down is to obtain bids from contractors, but the contractors will need a good set of specifications to be able to quote an accurate price. New Allegany County Bridgeby Roy R. Pedersen, PE Allegany County will be building a new structure next year (1999) to replace County Bridge 24-6, on County Road 10, in the Town of Scio. The NYSDOT provided primary funding as well as design guidelines for this bridge. The County is supplying the balance of the project funding. There is an October bid date set for the bridge. The road will be realigned to provide a 55mph design speed. The present bridge alignment requires two sharp turns to cross the stream. The new alignment will make the stream crossing much safer. It will also allow the present bridge to carry traffic until the new one is complete, thereby eliminating the need for a temporary detour structure. Due to the skew of the new bridge, it will be nearly 200ft long. The new bridge, designed in metric units, will feature a curved alignment deck, with superelevation to allow safer traveling through the curve. The bridge deck will be curbless to allow the water to run off and not harm the girders. The girders are of different sizes due to the curve. They will be 8ft tall, with flanges up to 3ft wide. Varying sub-surface conditions on either side of the stream required one abutment to need piles under it, while the other side will rest on the bedrock. The deck of the new bridge will utilize HP or high performance concrete. Class HP concrete is a modification of Class H concrete which substitutes 20% Class F Fly Ash and 6% Microsilica for cement. The water/cement ratio is .40. The use of the fly ash and microsilica has reduced permeability by approximately 70%. The lower water/cement ratio has helped reduce cracking by approximately 98%. By using the Class HP concrete the life of concrete bridge decks should be extended from 20 years to 50 years. Although the cost is higher (10%-20%) than Class H concrete the extended service life will more than recoup the cost of the investment. |