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HomeMy WebLinkAboutClass A Waiver - SWG Letters / Memos William L Russell 200 E Arellem Rd. Union Wa 98592 360-898-3773 Fax 360-898-3774 WASTE WATER DESIGNS LIC.5100184 Jan. 31, 2008 Mason County Department of Health 426 W. Cedar Street P O Box 1666 Shelton WA 98584 Parcel # 32330 51 06007 Subject - Class A Waiver request for Michael McGraw. NOTE this site already has an approved gravity system for a 3 be3 Broom home that was installed in July 1980 and is almost in unused condition. And it is just beyond the 50 foot set back line. See attached original plot plan As part of the mitigation measures to help comply with the new standards, please consider the following. The bottom of existing drainfield is 3.5 feet± down in the soil. This means that it is just a short distance away from the underlying better sandy soil we encountered on the day we dug the test hole. Hence the system is almost a sand filter system now. OPTION 1 Permit the installation of this bottomless sand filter design as a replacement for the old system and allow the building permit application to proceed. This new design is just beyond the 50 foot set back line. Drainfield failure is not likely to happen, no matter what kind of aeration device is installed. Due to the fact the aeration is the means that sand filters are recovered, when they have failed from ordinary septic tank effluent. Since a sand filter when properly built already meets treatment standard A it is only the use of sub-standard or the lack of quality materials that is rated at standard B. As quoted from a person at the WOSSA meetings. This system due to lack of space must be installed in the same area as the gravity system. Meaning that the old septic tank will be removed and the existing nearly new drainfield will be destroyed. OPTION 2 Due to need to locate the tanks near the tide waters of Hood Canal every precaution must be taken to have water proof tanks and connections to the tanks. Even though the location of the bottom of the tanks will be above the high tide line. Hence the following precautions shall be taken to water proof these tanks. PROCEDURES TO WATER PROOF TANKS: At the point of manufacture have the required tanks set aside without the lids installed. First acquire a supply of Grancrete. This is the trade name for a none toxic cement that was developed by NASA to in-case radio active material for permanent storage. It is impervious to all known household cleaning products and including salt water. It has a very high strength in that one inch thickness is equal to 4 inches of concrete. When properly applied to cement it is absolutely water proof. Once it has taken a set, the only way to remove it is to grind it off. It cannot be chilled off with ordinary tools. This would be placed with a trowel, similar installing plaster to a depth of 3/8f of an inch thick on the flat surface's with a % inch fillet in all of the corners. This will not only water proof the tank but also add tremendous strength to the tank. OPTION 3 RESERVE DRIP LINE SET BACK FROM PROPERTY LINES FROM 5 FEET TO 2 FEET; This is needed in order to obtain the maximum square footage that is needed in the limited space available. The effluent will be pre treated to treatment standard B WITH MORE THAN 24 INCHES OF VERTICLE SEPARATION. A test hole dug by this designer reveled 48 inches of really nice medium sand. I covered this hole up due to the request of a neighbor. And was told that the route from above to this part of the McGraw was over his property. So the only access to this area now is to climb up the 73% slope. Also it is possible to install a reserve area on the 73% slope with a 10 foot set back from the water line. Owner states that if the septic mitigation measures are meet (approved) that the planning and building department will allow a reduced set back for the proposed new building. Thank you William L Russell � vl ;7� y,•o wash•:?t Q't� ticy� O C.WILUAM LESLt RUS$ELL,„ ?� LICENSED DESIGIJEF2 EXPIRES 12/17/6