DEPARTMENT OF PLANNING AND ZONING
Zoning Administration Division
Ordinance Administration Branch
12055 Government Center Parkway, Suite 807
Fairfax, Virginia 22035-5505
(703) 324-1314 Fax (703) 803-6372
DATE: November 20, 2003
TO: William E. Shoup, Zoning Administrator
Zoning Administration Division
Department of Planning and Zoning:
FROM: Bruce G. Nassimbeni, Director
Environmental and Facilities Review Division
Office of Site Development Services
Department of Public Works and Environmental Services
SUBJECT: Highland Estates REFERENCE: Letter from Carl L. Sell, Jr., Dated November 7, 2003 addressed to You
In response to the note from Jack Reale, of your office, dated November 13, 2003, requesting a response from the Department of Public Works and Environmental Services on the fourth paragraph of the referenced letter, we offer the following.
Highland Estates has incurred a density penalty that resulted in the loss of one buildable lot. The property is zoned R-3 and has an area of 3.9126 acres, without the density penalty 11 buildable lots would have been allowed instead of the 10 lots allowed after taking into consideration the density reduction due to the presence of "marine clays" on the subject site. The Zoning Ordinance (Chapter 112-2-308.2C) requires a reduction in density when a site consists of 30% or more of "marine clays," the reduction is 50% for the area that consists of "marine clays" that exceeds 30% of the site.
ACCORDINGLY: Area of site: 3.9126 acres. 30% of the area of the site: 1.1738 acres. Area of site consists of "marine clays": 50% or 1.9563 acres. Since the area in "marine clays" is greater than 30% of area of the site (50% is greater than 30%) then a density penalty applies. 1.9563 acres - 1.1738 acres = .7825 acres (area of "marine clay" above 30% of site). 50% of.7825 acres = .39125 acres or .3913 acres (penalty). 3.9126 acres - .3913 acres = 3.52135 acres or 3.5214 acres (area of site less penalty). The density would be based on 3.5214 acres. The site is zoned "R-3", 3.5214 acres x 3: 10.5642. Therefore 10 lots are allowed with a density of 2.84 lots/acre (10/3.5214 = 2.8397 or 2.84), which is under 3 lots/acre as allowed.
As was stated in the referenced letter, the developer did provide a soils report for the project. The soils report is not used to calculate density or density penalty. The Subdivision Application Procedure and Approval Process is stated in The Code of the County of Fairfax, Virginia (County Code), Section 101-2-1, it specifies that in order to subdivide land in Fairfax County, the applicant is to provide a preliminary plat. Density calculations are performed at that time using current County soils maps (which is the best information available at the time). The construction plan, of which soils reports is a part, is to be submitted only after approval of the preliminary plat. We believe that was the case in this situation. The use of boring logs in calculating densities is not practical at this time, for it will require defining the minimum number of borings per acreage, the location of the borings (upslope, downslope), the depth of borings, and most importantly defining a non-technical term "marine clays" with the use of technical terms that have been standardized e.g. CH, MH, and other USCS classifications. This will be very complicated. Presently, the County soil maps are the most practical document that is used in defining the extent of marine clays on any site. The use of any other type of information will require major changes to the County Code. The County Code was applied correctly in this case.
If you have any further questions, please contact Gursharan Sidhu, Chief Site Review Engineer, Environmental and Facilities Review Division, at extension 4-1720.
cc: Jack Reale, Senior Assistant to the Zoning Administrator, ZAD, DPZ
Gursharan Sidhu, Chief Site Review Engineer, EFRD, DPWES
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