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HomeMy WebLinkAboutWetland Delineation 701043014WESTEC r COMPANY ry Environmental Consulting - Site Permitting January 12, 2018 Ms. Lauri Comen and Madeleine Wasson 2425 SW 112"' Street Burien, WA 98146-1964 Dear Ms. Comen and Mrs. Wasson RECEIVE.: DEC 10 2018 JEFFERSON COUNTY ENVIRONMENTAL PUBLIC HEALTH This letter report documents site conditions found on your property on Carl Johnson Road in Quilcene, Washington (Parcel # 701-04-3014). As you requested, Westech Company investigated the property during November and December 2017 to check for the presence of wetlands and streams in the vicinity of the existing cabin and septic system. The Site location is shown in Figure 1 (attached). We carried out fieldwork on November 14 and November 20. Site reconnaissance and fieldwork were conducted by Dr. G. Bradford Shea and Mr. Paul Ruben. Wetland boundaries were flagged with pink "Wetland Delineation" Tape Boundary points were marked using GPS technology with a Garmin Oregon Series GPS meter. Waypoints along the wetland boundary were then mapped using Google Earth Pro. The wetland boundaries are shown in Figure 2. Findings Wetlands are determined by three factors, vegetation, soils and hydrology. Wetland boundaries were determined through analysis of wetland vegetation as a primary indicator and confirmed with soil analysis taken with a "wetland" shovel for shallow 18-24 inch deep test pits. Hydrology was also checked for saturation in these test pits. Vegetation Vegetation near the existing cabin and septic system consisted of grass and weedy species typical of a former lawn area bordering the parking area and entry driveway. Beyond this, to the south, east and west, were wetland plants varying from open, emergent wetland plants, to shrub -scrub and forested wetland vegetation. P.O. Box 2876, Port Angeles, Washington 98362 - Telephone: (360) 565-1333 email: brad@westechcompany.com Ms. Lauri Comen and January 12, 2018 Page Two Madeleine Wasson RECEIVED DEC 10 2018 JEFFERSON COUNTY ENVIRONMENTAL PUBLIC HEALTH Dominant species included red alder (Alnus rubra), Western red cedar (Thuja plicata) and cottonwood (Populus balsimifera) in the wetland tree layer. The shrub layer was dominated by salmonberry (Rubus spectabi/is), while the herb layer included soft rush (Juncus effuses), reed canary grass (Phalaris arundinacea), slough -sedge (Carex obnupta) and creeping buttercup (Ranunculus repens). Wetland vegetation was found to be fairly diverse. Soils The Natural Resource Conservation Service (NRCS) maps the Site as having two soil types. The area near the cabin is mapped as Alderwood sandy gravelly loam, 0-15 percent slopes (AIC). The area northwest of the cabin area is mapped as Alderwood gravelly loam 0-15 percent slopes (AmC). These soils are both moderately well drained and associated with a glacial till (hardpan) layer, usually at depths of 20-40 inches. While these soils are not technically hydric, they may have inclusions of hydric soils. Also, the till layer, when close to the surface, may cause surface soils to be saturated, particularly on hillslopes. Site soils in the wetland were found to be gravelly loam near the surface, underlain by sandy clay with a depleted matrix in the lower root zone (6-18 inches). These soils showed a depleted matrix characteristic of hydric soils. Evidence of redoximorphic features (mottles) were also present. Upland soils were found to be sandy clay soils with an underlying restrictive hardpan layer (glacial till). Hydrology Water table was present at six (6) inches in most areas of the wetland. While the period sampled was one of significant rainfall, water table is clearly present within the root zone of the wetland plants (above 24 inches) throughout the winter and early spring period, thus qualifying for wetland hydrology in accordance with criteria of the U.S. Army Corps of Engineers (USACE 198712010). Surface and near surface soils were saturated inmost wetland areas within the root zone. Results The Site was found to have significant near surface water due to winter precipitation and slope drainage. These conditions have created wetlands on the hillside, essentially surrounding the existing residence, except in the direction of the entrance driveway. The wetland boundary is shown in Figure 2. P.O. Box 2876, Port Angeles, Washington 98362 - Telephone: (360) 565-1333 email: brad@westechcompany.com Lauri Comen and Madeleine Wasson January 12, 2018 Page Three To the south of the residence, a small drainage is located within about 25 feet. To the west, wetlands are set back further but are 50-60 feet from the residence. To the east is a small pond at a distance of about 50 feet, however, some wetland characteristics are found closer to the residence. To the north, the entry road breaks up the wetland line, however, many areas are in wetlands in this area as shown on Figure 2. Wetlands were rated in accordance with the Washington Department of Ecology Rating system This was a preliminary rating for this project for Site Planning purposes. The wetlands were rated as Category IV wetland. Conclusions and Recommendations The wetlands were rated as Category IV wetlands, which will require a 40 foot buffer zone for moderate impact land uses, including a single family residence. The owner may wish to either repair or put in a new septic system for the existing cabin. The location of the current septic system is within the required 40 foot buffer, as are most other potential locations for a new septic system. Therefore, some form of buffer reduction or waiver will be necessary in order to repair or replace the septic system. It will also be necessary to complete a full Wetland Delineation Report due to the proximity of the wetlands on the Site to the septic system and the existing cabin. Westech recommends that a Wetland Delineation Report be completed, including buffer reduction as necessary for completion of a septic system. Methods for buffer reduction can include buffer averaging, buffer reduction with mitigation, or completion of a Critical Areas Stewsardship Plan (CASP). Please let me know if you have any questions regarding this report. Thank you. Sincerely, G. Bradford- hea, Ph.D. REPA, ABI Senior Environmental Scientist/Ecologist GBS/ms Attachments RECEIVED DEC 1 0 2018 3EFFEpSON COUNTY ENVIRONMENTAL PUBLIC HEALTH P.O. Box 2876, Port Angeles, Washington 98362 - Telephone: (360) 565-1333 email: brad@westechcompany.com c-�",�Jlthlbli Lo p x 4 r 1