Crescent City, CA DESIGN STANDARDS

All design of sewers, connections to sewers, pretreatment facilities and appurtenances which are directly or indirectly connected to the city sewer and wastewater treatment system shall be designed in accordance with all state laws, city ordinances and regulations and in accordance with generally accepted engineering practice. Any works to be constructed within a public right-of-way shall be designed by an engineer licensed to practice in California. Any works on private projects connected to the city system may require design by an engineer licensed to practice in California, when in the opinion of the city engineer the complexity of the system requires such professional knowledge.

No two adjacent buildings fronting on the same street shall be permitted to join in the use of the same lateral sewer. Every building must be separately connected with a public sewer if such public sewer exists in the street upon which the property abuts. Where such connections preexist these regulations, they must be permitted until sale of the parcel, at which time a separate lateral sewer shall be provided for the sold parcel.

Old lateral sewers may be used in connection with new buildings only when they are found, upon examination and test by the city engineer, to meet all requirements of this ordinance and the city standards.

In all buildings in which any building sewer is too low to permit gravity flow to the public sewer, sanitary sewage carried by such building sewer shall be lifted by artificial means, approved by the city engineer and discharged to the public sewer at the expense of the owner. Adequate antibackflow devices shall be installed by the applicant.

The connection of the building sewer into the public sewer shall be made at the lateral or "T" branch, if such lateral or "T" branch is available at a suitable location. Where no properly located "T" branch is available, a neat hole may be cut into the public sewer to receive the building or lateral sewer, with entry in the downstream direction at an angle of forty-five degrees. A wye saddle shall be used for the connection and in no case shall the pipe protrude inside the main sewer. A smooth, neat joint shall be made, and the connection made secure and watertight by encasement in concrete. The connection to the public sewer shall be made in the presence of the city engineer and under his supervision and direction. Any damage to the public sewer shall be repaired at the cost of the applicant to the satisfaction of the city engineer.

All excavations for a lateral sewer installation shall be adequately guarded with barricades or lights so as to protect the public from hazard. Streets, sidewalks, parkways and other property damaged in the course of the work shall be restored in a manner satisfactory to the city engineer.

All domestic or sanitary wastewaters from rest rooms, showers, drinking fountains, etc., shall be kept separate from all industrial waste-waters until the industrial wastewaters have passed through any required pretreatment system or device. A control manhole of a design approved by the city engineer shall be furnished and installed by certain designated industrial wastewater dischargers to facilitate inspection, sampling and flow measurements by personnel of the city, This control manhole shall be located off the industrial premises or if within the plant fence, a special locked gate adjacent to the manhole and at a location approved by the city shall be provided, with keys to the gate lock given to the city. Unrestricted access to this control manhole shall be available to authorized personnel of the city at all times. The control manhole may be used as a junction manhole for domestic sewage and industrial wastes provided the junction occurs downstream of the sampling or flow measuring point.

Each discharger shall provide protection from accidental discharge of prohibited materials or other wastes regulated by this ordinance. Where necessary, or as directed by the city engineer, retention basins, dikes, storage tanks or other devices designed to eliminate, neutralize, offset or otherwise negate the effects of prohibited materials or waste discharges in violation of this ordinance shall be installed. line.

Lateral sewers shall be maintained by the owner of the property served up to the front property

All lateral sewers shall be tested in the presence of the city engineer by filling the line with water and inspecting for excessive leakage. Fittings, plugs, water and labor or testing shall be furnished by the person constructing the sewer. All lines showing excessive leakage shall be repaired or replaced at the expense of the person doing the work and shall be done at the direction and to the satisfaction of the city engineer.

The following technical provisions shall be used in the design of sewers connected to or a part of the city sewage system. For facilities for which specific requirements are not provided, the city engineer shall determine the design parameters:

Sizing of all sewers shall be based upon a complete drainage study of the present proposal as well as all existing and potential up-stream contributing areas. Minimum main size is six inch diameter.

Sewers shall be designed to handle a per capita average flow of one hundred gallons per day for residential areas.

Commercial and industrial areas will require the design of sewers to handle the quantities discharged as determined by the applicant's engineer with the approval of the city engineer.

Design of the sewer lines will be based upon peak flows in accordance with the standard practice adopted by the American Society of Civil Engineers in their manual on Engineering Practice No. 37 latest revision.

All sewers shall be designed to flow two-thirds full under peak design conditions.

The minimum size of a lateral sewer shall be four inch diameter. The minimum slope of a lateral sewer shall be a minimum five tenths foot per one hundred feet and the minimum cover shall be twenty-four inches unless a variance from these standards is given in writing by the city engineer.

Sewer Slopes. The minimum slopes of pipe are as follows:

Size of Pipe	Minimum Slope
6 inch	.0034
8 inch	.0024
10 inch	.0020
12 inch	.0014
15 inch	.0012

All sewer mains and laterals shall be vitrified clay pipe. This pipe shall be rubber gasket, wedge lock, band seal or equal.

Manholes shall be used to make all turns.

10.

Manholes on straight sewer lines shall be placed a maximum of four hundred feet center to center.

11.

Sewer mains in curved streets shall be a minimum of twenty feet from the nearest property line and shall be on a minimum two hundred foot radius. Manholes between tangents shall not be closer than twenty-four feet to the nearest property line.

12.

Manhole covers in undeveloped areas will be set one foot above existing grade.

13.

All manhole stubs shall be shown on the plans by size.

14.

Clean-out or manhole shall be used on dead-end lines.

15.

All sewer mains in the street shall be in a location designated by the city engineer.

16.

All sewer laterals shall be extended to the property line and shall be a minimum four inch diameter but in no case shall the sewer lateral on public property be smaller than the lateral on private property.

17.

The lateral invert at the curbline shall be three feet below the curb flowline grade.

18.

Lift stations shall be avoided where possible. However, it is recognized that they may have to be used and the following design requirements are to be adhered to in their design:

Pumps or ejector units shall be provided in duplicate arranged for positive priming.

Capacity shall be provided to handle ultimate peak flow from the tributary area. When the tributary area exceeds three hundred acres the capacity shall be provided to handle the peak ultimate flow with the largest pump out of service. Staged installation of pumps is allowed providing space is provided for future installation.

Access shall be provided to the site for removal and repair of equipment.

A means of dewatering force mains shall be provided.

An overflow device will be provided if possible as approved by the city engineer.

Forcemains shall be designed so as to be able to pass the peak flows without excessive pressures, and the materials shall be corrosive resistant to the type of sewage being delivered through them. Force mains shall be designed as to obtain a minimum of three feet per second velocity during the pumping period.

19.

New sewers shall have a maximum allowable infiltration/exfiltration rate of two hundred gallons per day per inch diameter of sewer per mile.