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Home My WebLink AboutLog009 Section 3 . . . Parametrix ~(~u~ 'I ! '~"Oo""""'''' -'T~O"J'~re I~t~ !1 I I""lf': - , ~ - 5 liJu5 t" i I ENGINEERING. PLANNING. ENVIRONMENTAL SCIENCES 411 108th AVENUE NE, SUITE 1800 BELLEVUE, WA 98004-5571 T. 425 . 458 . 6200 F. 425 . 458 . 6363 L...-" , "''"V\'Vl.'.par~mctrix.com TECHNICAL MEMORANDUM Date: To: June 17, 2005 Jim Hasslinger Project Manager Paul Anderson Wetland Delineation Amendment From: Subject: cc: Project Number: 256-1820-009 04/03 Project Name: Beckett Point Sanitary Improvements INTRODUCTION The Jefferson County Public Utility District NO.1 (PUD No.1) has retained Parametrix to design a large on-site septic (LOSS) system for the shoreline community of Beckett Point. This memorandum has been prepared at the request of Jefferson County (County) Department of Community Development (DCD) staff as an amendment to a wetland delineation report (Brooks 2000) prepared for the Beckett Point Fisherman's Club, Inc. Beckett Point is located in eastern Jefferson County, southwest of Port Townsend, Washington on the (Sections 23 and 24, Township 30N, Range 2W) (Figure 1). The Beckett Point community is located on the perimeter of a low-relief, cuspate foreland (spit) on the eastern shore of Discovery Bay. Elevation on the spit is less than 40 feet mean sea level (MSL), the lowest elevation contour shown on the USGS Gardiner, Washington quadrangle. A wetland complex, approximately 15 acres in size, is found in the interior of the spit. Land within the Beckett Point community is subdivided into approximately 165 lots, 90 of which have the potential to be connected to the proposed on-site treatment system. Currently, homes at Beckett Point are serviced by individual septic systems of varying ages and condition. The proposed project will upgrade the sanitary septic system for a significant proportion of the homes at Beckett Point, potentially protecting water quality and sensitive environmental resources in Discovery Bay and the project area. The preliminary septic system design proposes installing two completely independent LOSS systems. The community will be separated into northern and southern collection systems which will be divided by the existing lagoon/wetland in the center of the community. Each collection system will utilize a small grinder pump station at each house and pumping via a low pressure sewer system force main, to be constructed within the prism of Beckett Point Road, to the first of Beckett Point Sanitary Improvements Wetland Delineation Amendment 1 256- I820-oo9 June 2005 9 :1 j J [;".0. . two submersible sewage lift stations. The first lift station being at elevation 70 feet MSL and the second lift station at elevation 210 feet MSL. The sewage will be conveyed to large on-site septic tanks located in the uplands at 280 feet elevation MSL above the beach community. Dosing tanks will pump the septic tank effluent to large pressure drainfields located on the eastern one-third of the property. The drainfields will be between 275 and 375 feet elevation MSL and no closer than 600 feet horizontally to the nearest shoreline. The drainfields will be traditional trench-type pressure drainfields. APPLICABLE LAWS AND REGULATIONS The Jefferson County Unified Development Code (UDC) (Ordinance No. 06-0510-04) defines wetlands as an environmentally sensitive area (9 3.6.4(a)) and regulates activities within wetlands and/or their buffers. Section 3.6.9 of the UDC includes the identification, rating, and categorization of wetlands as well as the requirements for wetland reports, wetland buffers, and mitigation. At the federal level, wetlands and streams are protected by Section 404 of the Clean Water Act (CWA), which regulates placement of fill in waters of the United States. The U.S. Army Corps of Engineers is responsible for implementing permits under Section 404 of the CW A, which regulates the placement of- dredged or fill material in wetlands. Activities that affect wetlands and streams may also require a water quality certification (Section 401 of the CWA), which is implemented at the state level by the Washington State Department of Ecology (Ecology). Ecology reviews projects for compliance with state water quality standards and makes permitting and mitigation decisions based on the nature and extent of impacts, as well as the type and quality of wetlands/streams being affected. . A wetland delineation in 2000 (Brooks 2000) identified a palustrine wetland complex, approximately 15 acres in size, within the central portion of Beckett Point. This wetland was rated as a Class II Wetland under the 1994 Jefferson County Interim Critical Areas Ordinance (CAO). Updates to the Jefferson County CAO were adopted in 2004 (Ordinance No. 06-0510- 04), since completion of the 2000 wetland delineation. During an October, 2004 pre-application meeting at Beckett Point, County DCD staff requested that an amendment to the 2000 delineation report be prepared reflecting the updated code requirements. This memorandum assesses potential project related wetland and buffer impacts and proposes mitigation based on the 2004 UDC revisions. For a more detailed description of the wetland, see Brooks (2000). The UDC (9 3.6.9(a)(2)) designates wetlands by their category under Ecology's 1993 wetland rating system for Western Washington and specifies a 100-foot standard buffer for Category II Wetlands greater than 2,500 square feet in area (9 3.6.9(d)(5)). Category II Wetlands under the 1993 Ecology rating system are those wetlands that have a documented occurrence of state or federally listed species, or include state designated priority habitats or species; or provide significant functions not easily recreated; or with a habitat score greater than or equal to 22 points on the field data form; or that have been designated as a habitat of local significance (Ecology 1993). At approximately 15 acres in size, the Beckett Point wetland delineated by Brooks (2000) is subject to the provisions of UDC 9 3.6.9 and would be regulated by the County. . Beckett Point Sanitary Improvements Wetland Delineation Amendment 2 ~ r ") [< ' i l) r--~_I. ;~ .~.~ ZGOI I' l~02:: ...,"___.-.-...... .,,_J Ik"-Y q ,..,~-"~:,:.:__".,.,'~....,_:....,.:,_..,-.::,',.;,._.'"',..~fr&,. .. ~ . '''~'''_''N_ . e L N C:\Doctme '1J aid Sietlhga:"'dt 1p31\1Il{ Docllfte ,."'rojec1J'lBtdtt'tt pOlltwe....udiJ.apr PSA 6116.05 Figure 1. Vicinity Map, Beckett Point, Jefferson County, Washington. (1f- !l ) ,I I ! 1 ! i I l".~,^, "' _ r-, i;;: i""'\ i l: ir'\\l II!I J) -- I J . Beckett Point Sanitary Improvements Wetland Delineation Amendment 3 256, I 820,009 June 2005 lo"", ' . . . POTENTIAL PROJECT IMPACTS AND MITIGATION A wetland in the interior of Beckett Point, delineated by Brooks (2000), is within approximately 25 to 50 feet of homes on the landward side of Beckett Point Road. Work areas at Beckett Point will be restricted to existing improved areas, including the prism of Beckett Point Road, private driveways, and landscaped areas at homes to be included in the upgraded septic system. Proposed improvements to the Beckett Point septic systems will not involve direct wetland impacts. No wetland filling, dredging, or vegetation clearing will be required. Best management practices, including the use of sedimentation fencing, will be used to protect water quality for local area waters and the wetland during construction. Once completed, the septic system upgrade will benefit water quality and protect natural resources by reducing the number of septic systems and by decreasing potential nitrate loading and fecal coliform contamination of the wetland and Discovery Bay by older individual septic systems. Discovery Bay beaches, including Beckett Point are currently closed to the harvesting of butter clams (Saxidomus giganteus) due to shellfish biotoxin contamination (DOH 2005). Although the proposed project will not directly impact the wetland, installation of the Beckett Point sanitary system will impact the wetland buffer. Ninety percent of approximately 3,500 feet of Beckett Point Road on the spit are within the 1 OO-foot wetland buffer (Figure 2). Roughly 300 feet of road at the western end of the spit are outside of the wetland buffer. Likely project related buffer impacts include excavation, stockpiling of excavation spoils or construction materials, and vegetation clearing. These impacts will be limited to existing improved and landscaped areas on the spit at Beckett Point. No native vegetation will be cleared on the spit for this project. Vegetation clearing in the upland for the septic drainfield is outside of the 100- foot wetland buffer. Because there will be no direct wetland impacts and native vegetation will not be cleared within the wetland buffer, no compensatory mitigation is planned or proposed. After installation of the force main and hookups for individual homes, disturbed areas will be graded to the pre- construction contour. Paved driveways and Beckett Point Road will be resurfaced with pavement. Disturbed vegetated areas will be reseeded in compliance with the Ecology stormwater manual (Ecology 2001). For example, as outlined in the Ecology stormwater manual, revegetation of disturbed areas following construction will likely include the following: tall fescue (Lolium arundinacea), bentgrass (Agrostis spp.), redtop (Agrostis alba), and white clover (Trifolium repens). r;::;'\ r : ': . '. . " H= ~ I ,Jj '-__1-_ ~ "j'l I , - ~~L~ Beckett Point Sanitary Improvements Wetland Delineation Amendment 4 256,1820,009 June 2005 ~. .~ . e . /' " 100-foot Wetland Buffer N Estimated Wetland Boundary ~ N 200 , o 200 400 Feet C~DOClmt.. aUI 9I!tllt9l"~ndil! 1p3f\1Iy' DoCfmtl.\proltc."edle1tPOlliftl'lloeltulU.aprPSA6/16,o5 Figure 2. Estimated wetland boundary and 1 OO-foot buffer, Beckett Point. [iL ! I '\\ AU;; - 5 2005 ~ I, ~~ "..,.~_.~"",.._..-.-.....--.--~ J ,- \ I l,___.. .-_....-..~<.....'~...,-----.- Beckett Point Sanitary Improvements Wetland Delineation Amendment 5 256- I 820-009 June 2005 ~ .b. ~ REFERENCES Brooks, K.M. 2000. Wetlands delineation and ranking. Pacific Rim Aquatic Environmental Sciences, Port Townsend, Washington. DOH (Washington State Department of Health). 2005. Recreational shellfish beach closures due to biotoxins or pollution. Available at: <http://www.doh.wa.gov/ehp/oehas/EHA_fish_adv.htm>. Olympia, Washington. Accessed June 17,2005. Ecology (Washington State Department of Ecology). 1993. Washington State wetlands rating system, western Washington. Second Edition. Publication Number 93-74. Olympia, Washington. Ecology (Washington State Department of Ecology). 2001. Stormwater management manual for Western Washington, Volume V, Runoff Treatment BMPs. Publication No. 99-15, Water Quality Program, Olympia, Washington. ~ ww-~ . . lE fr'J ': <~rl, Illlj ~.~~f \ ,.----,,-__ __._.. .,_J i [ \."=""""-'"'--"""'~'''<' ~ Beckett Point Sanitary Improvements Wetland Delineation Amendment 6 256-1820-009 June 2005