13.28.150 - Design criteria and construction standards.

The department shall ensure that sewer facilities design and construction standards satisfy the standards of the most current department design and construction specifications, or as prescribed and interpreted by the director.

(Res. 144-99 Art. V, § 5.01, 1999).

13.28.160 - Connection to public sewers.

All connections to the public sewers of the county shall be made in a permanent and sanitary manner in accordance to the provisions of this code and shall be sufficient to carry all the wastewater of every kind from the building or structure into the public sewer.

(Res. 144-99 Art. V, § 5.02, 1999).

13.28.170 - Repairs to connections.

For properties within the North Bay - Case Inlet service area, any needed repair to a building sewer or connection to a public sewer shall be made within thirty days after the date of mailing or personal service of a notice by the director to the owner of the property served notifying such owner to make such repair. In the event of an emergency, the director may establish a shorter period of time for the repair to be made or, if the owner cannot be located or does not promptly make such repairs, the county may make the repairs under the procedures of this code and charge for the work based on the staff's and/or contractor's hourly rate.

(Res. 144-99 Art. V, § 5.03, 1999).

13.28.180 - Connection standards.

(a)

Gravity Service Connections.

(1)

Old building sewers, including septic tank lines, may be used only when they are found, on examination and test by the director to meet all requirements of the code.

(2)

The building sewer shall conform to all county and state building codes and/or with the manufacturer's recommended practices, whichever is more restrictive. New sewer pipe and fittings at a minimum shall be PVC and shall meet or exceed ASTM recommended specifications D3034-73, SDR 35, current revisions.

(3)

Connections between dissimilar pipe materials shall be by adapters approved by the director or his agent. The first fitting at the connection of the building sewer to the public sewer service connection shall be a tee, furnished by the owner. Immediately after installation of the tee, an expandable watertight plug shall be installed in the tee branch connected to the public sewer. Such plug shall remain in place during construction and testing of the building sewer. After the plug has been removed, the tee riser shall be extended vertically to within six inches of finished ground surface and shall be sealed with an approved cap or plug. The riser shall be used as an auxiliary cleanout.

(4)

The size and slope of the building sewer shall be subject to the approval of the director, but in no event shall the diameter be less than four inches. The slope of said four inch pipe shall not be less than one-quarter inch per foot, unless approved by the director. In no case shall the slope of four-inch pipe be less than one-eighth inch per foot. A minimum of eighteen inches of cover shall be maintained over the top of service pipe at all times.

The building sewer shall be laid at uniform grade and in a straight alignment insofar as is possible. Changes in direction shall be made only with curved pipe no greater than "forty-five-degree bends." All pipe shall be laid on a four-inch granular base of a three-quarter-minus rock, pea gravel, sand or combination thereof.

Whenever possible, the building sewer shall be brought to the building at an elevation below the basement floor. In all buildings in which any building drain is too low to permit gravity flow to public sewer, sanitary sewage carried by such building drain shall be lifted by an approved means and discharged to the building sewer.

(5)

All excavation required for the installation of a building sewer shall be open trench work unless otherwise approved by the director. No backfilling of the trench shall be done until inspection by the county has been conducted.

(6)

All joints and connections shall be made gastight and watertight.

(7)

The applicant for building permit shall notify the director when the building sewer is ready for inspection and connection to the public sewer. After final approval and testing of the building sewer by the director, the owner shall make the final connection to the building drain, unless otherwise authorized by the director. A thirty-minute internal hydrostatic test may be required on all building sewers before connection is made to the building drain. All water plugs and other facilities for making the test shall be furnished by the applicant. Minimum head over the top of the pipe shall be two feet and a maximum allowable leakage shall be four gallons per hour per one hundred feet.

(8)

Any structure having a plumbing outlet that serves fixtures with flood level rims located below the elevation of the next upstream manhole cover shall install an approved backwater valve.

(b)

Grinder Pump Installations.

(1)

Any structure requiring a grinder pump unit shall utilize a unit conforming to Mason County standards. The grinder pump unit shall be subject to approval at the same time as the building permit.

(2)

Service lateral piping attached to the grinder pump unit and extending to the valve vault shall be one and one quarter-inch HDPE pipe with a working pressure exceeding one hundred sixty psi at 73.4 F and a minimum SDR of eleven. The HDPE pipe shall be installed in a continuous length from the grinder pump unit to the valve vault.

(3)

All grinder pump installations shall require a valve vault located approximately at the county or state right-of-way. The valve vault shall conform to Mason County standards for either non-traffic or H-20 traffic conditions. The type of valve vault shall be determined at the time of building permit submittal. Each valve vault shall contain at a minimum a PVC ball shut-off valve and also a PVC check valve at identified locations.

(4)

All joints and connections shall be made against and watertight. Transition couplings from HDPE to other material shall be rated for one hundred fifty psi.

(5)

The applicant for the building permit shall notify the director when the grinder pump installation is ready for inspection and connection to the public sewer. The applicant shall demonstrate operation of the grinder pump with water over a complete "on/off" cycle and also demonstrate the operation of the alarm light by overfilling the wet well. After final approval and testing of the grinder pump, by the director or his agent, the owner shall connect the building sewer to the grinder pump wet well and the HDPE service lateral to the public sewer system. Both of these connections shall be approved by Mason County prior to backfilling of the trench.

(c)

Separation for Water and Sewer Piping.

(1)

Requirements for separation between water lines and sanitary sewers are shown in the "Criteria for Sewage Works Design," Washington State Department of Ecology (December 1998). In general, a minimum horizontal separation of ten feet between sanitary sewers and any existing potable water lines and a minimum vertical separation of eighteen inches between the bottom of the water line and the crown of the sewer shall be maintained.

(2)

Where local conditions prevent the separations described in subsection (c)(1) of this section, the sewer shall be installed in a separate trench with a minimum of eighteen inches of vertical separation between the crown of the sewer and the bottom of the water line.

(3)

Where a potable water well exists, the grinder pump and service lateral piping shall be located outside of a fifty-foot radius from the well. If the service lateral piping cannot be located outside of this radius, the service lateral piping shall be encased with a two-inch HDPE piping, SDR eleven, within the fifty-feet radius.

(4)

Additional mitigation efforts may be required by the director for high ground water, unstable soils, or other unusual site conditions.

(Res. 144-99 Art. V, § 5.04, 1999).

13.28.190 - Abandonment/modification of existing septic tanks.

(a)

Abandonment of existing septic tanks or other sewage containers for the purpose of connecting to public sewers shall be conducted in conformance with WAC 246-272-1850.

(b)

Any existing septic tank utilized for an emergency overflow for a grinder pump unit shall be pumped by a licensed septic tank hauler. All tanks whose access opening is greater than eighteen inches below the surface shall be brought to eighteen inches below grade with twenty-four-inch diameter minimum concrete extension rings grouted to become watertight. Modifications, and connections to the existing septic tank shall be inspected by the county for watertightness prior to backfilling.

(Res. 144-99 Art. V, § 5.05, 1999).

13.28.200 - Information from the county.

The owner of any building shall be responsible for obtaining from the director the approximate location and elevation of the sewer wye, tee or stub at the point of connection and, in the case of new construction, for planning the building and plumbing to provide adequate slope for building connection to the side sewer stub. The applicant for permit shall be responsible for determining the available grade between plumbing outlet and sewer wye, tee or stub. All department supplied information shall be field checked by the owner/developer or his/her representative prior to design and/or commencing construction. The county is not liable for inaccurate information provided to the county.

(Res. 144-99 Art. V, § 5.06, 1999).

13.28.210 - Costs of building sewer or sewer line extension borne by owner.

(a)

Gravity Sewer Connections. All costs and expense incidental to the installation, connection, maintenance, cleaning, repair and/or addition to or of the building sewer shall be borne by the owner effective January 1, 2002. This responsibility includes paying all costs incidental to the aforementioned activities performed on all segments of the sewer and including but not limited to side sewer stub, sewer tee, sewer wye, and all other sewer appurtenances.

(b)

Grinder Pump Installations. All costs and expense incidental to the installation, connection and/or addition to or of the building sewer shall be borne by the owner effective January 1, 2002. This responsibility includes paying all costs incidental to the aforementioned activities performed on all segments of the sewer and including but not limited to side sewer stubs, sewer tee, sewer wye, grinder pump, service lateral, valve vault, and all other sewer appurtenances. Upon installation and testing of the grinder pump, the maintenance of the grinder pump, service lateral, and valve vault shall be the responsibility of the county. The building sewer shall be the responsibility of the owner.

(Res. 144-99 Art. V, § 5.07, 1999).

13.28.220 - Mutual maintenance agreement and easement.

If it is determined that a special condition(s) requires more than one separately owned residence to be served by a single building sewer, written authorization to do so must be obtained from the director after the owners of such properties have entered into a mutual use agreement. This document assuring that all properties involved shall have perpetual mutual easements for the building sewer, and having provisions for mutual maintenance and access for repair purposes, shall be signed by the recorded owners and acknowledged and recorded with the county auditor, and a copy thereof furnished to the director prior to the issuance of a permit for the approval of the building sewer.

(Res. 144-99 Art. V, § 5.08, 1999).

13.28.230 - Reuse of old building sewers.

Old building sewers, may be used only when they are found, on examination and test by the director, to meet all requirements of this code. This examination and test shall be at the owner's expense. The owner or his/her agent shall demonstrate to the director that no connection to such building sewer line exists which conveys any material prohibited by county.

(Res. 144-99 Art. V, § 5.09, 1999).

13.28.240 - Protection of excavations and restoration of public property.

All excavations for building sewer or sewer line extension installations shall be adequately guarded with barricades and lights in accordance with state and county requirements so as to protect the public from hazard. Road, parkways and other public property disturbed in the course of the work shall be restored to original condition or better.

(Res. 144-99 Art. V, § 5.10, 1999).

13.28.250 - Commercial wastes—Control manhole.

When required by the director, the owner of any property served by a building sewer carrying commercial wastes shall install a suitable control manhole in the building sewer to facilitate observation, sampling and measurement of the wastes. Such manhole, when required, shall be fully accessible, safely located, and constructed in accordance with plans approved by the director. Such plans shall be in accordance with current county standard sanitary sewer specifications and standard plans. The manhole shall be installed by the owner at the owner's expense and shall be maintained by the owner so as to be safe and accessible at all times by the county.

(Res. 144-99 Art. V, § 5.11, 1999).

13.28.260 - Commercial wastes—Grease traps.

When required by the director, the owner of any commercial establishment found to be discharging excess oils, fats, and grease shall install a suitable grease trap in accordance with the latest edition of the Uniform Plumbing Code. Such grease trap, when required, shall be fully accessible, safely located, constructed and maintained in accordance with plans approved by the director.

(Res. 144-99 Art. V, § 5.12, 1999).

13.28.270 - Pretreatment of sewage.

(a)

When, at any time, it becomes necessary or desirable to discharge into the North Bay - Case Inlet sewer system any matter from any existing or proposed facility which does not conform to the standards as prescribed in the most current requirements of this code, the owner(s) of such facilities shall be required to pretreat such matter at owner(s) expense to a degree that will produce an effluent which will conform to the standard outlined therein and as amended from time to time or as prescribed and interpreted by the director.

(b)

Such pretreatment shall include grease traps, chemical or biochemical plants, sedimentation chambers and any devices which effect a change of any nature in the characteristics of the matter being treated. Any and all such devices and equipment shall be subject to the approval of the director and the Washington State Department of Ecology and shall not be put into operation nor revised in any manner without written permit or approval issued by the director, the Washington State Department of Ecology and other approving governmental agencies. (Any such device other than a grease trap requires approval from other governmental entities.) Such devices and equipment shall be provided with all necessary features of construction permit inspection of operations and testing of materials passing through other governmental agencies for such pretreatment facilities shall not guarantee that the pretreatment facility will operate as designed; the owner and/or the owner's engineer will assume this liability.

(c)

New plans and specifications and other pertinent information relating to proposed preliminary treatment facilities shall be prepared by a licensed professional engineer and shall be submitted for the approval of the director and the state of Washington, Department of Ecology and Department of Health when required by law. No construction of preliminary treatment facilities shall be commenced until such approvals are obtained in writing. Any expenses incurred by the county in reviewing such plans, specifications and information shall be paid by the property owner and owner's representative before the county's approval shall be granted.

(d)

All approval procedures, planning and design specifications, charges, fees and other requirements relating to pretreatment facilities shall conform to the provision outlined in the most current requirements of this code.

(Res. 144-99 Art. V, § 5.13, 1999).