Chapter 19.35
UTILITIES
Sections:
19.35.040 Installation – New rights-of-way.
19.35.050 Installation – Within or adjacent to existing, improved rights-of-way.
19.35.060 Water distribution systems.
19.35.070 Sanitary sewer systems.
19.35.080 Street illumination.
19.35.010 Purpose.
This chapter describes the design, installation, and location requirements for public and private utilities within the City of Ferndale. The City of Ferndale seeks to ensure that utilities are located in a manner that minimizes risks to life, health, and safety, that ensures the efficient delivery of services, provides for cost-effective maintenance and repair, and utilizes scarce land and natural resources effectively. Water is the critical utility within the City of Ferndale, and will receive priority for protection and ease of maintenance. Finally, it is the objective of this chapter, in concert with the City’s Comprehensive Plan, to identify the location of future utility lines and to ensure those utilities are extended through to adjacent properties to allow for the efficient expansion of services. (Ord. 2007 § 1, 2017; Ord. 1999 § 1 (Exh. 1), 2017. DS § 701)
19.35.020 Franchising policy.
Utilities to be located within the City street right-of-way shall be constructed in accordance with current franchise and permit procedures and in compliance with these standards. In their use of the right-of-way, utilities shall be given consideration after the traffic-carrying requirements of the streets which are, namely, to provide safe, efficient, and convenient passage for motor vehicles, pedestrians, and other traffic. Aesthetics shall be a consideration. As a matter of policy, placement of all utilities underground will be required in all urban development. (Ord. 2007 § 1, 2017; Ord. 1999 § 1 (Exh. 1), 2017. DS § 702)
19.35.030 Utility locations.
Utilities within the right-of-way on new streets shall be located as indicated below. Where existing utilities or storm drains are in place, new utilities shall conform to these standards as nearly as practical and yet be compatible with the existing installations. All utilities shall be buried at least 30 inches below finished grade, excluding storm drains which shall have a minimum cover of 12 inches. Where utilities are placed in the ditch area the buried depth shall be at least 36 inches below the bottom of the ditch. Exceptions shall be approved when necessary to meet the special requirements or restrictions. Utilities shall be extended through property to allow for future extension, expansion, and continuation of City’s distribution system or for consistency with Comprehensive Water System Plan and/or Comprehensive Sewer Plan.
A. Gas and Dry Utility Lines.
1. Gas and dry utilities shall be located behind the sidewalk, within a 10-foot easement outside of the City right-of-way.
2. Gas and dry utilities shall generally be located on the opposite side of the street from the City’s water lines.
3. Gas and dry utilities shall be designed and installed in a manner that does not conflict with existing or proposed stormwater facilities such as ditches, bioswales, or similar.
B. Sanitary Sewers. Sanitary sewers shall be located within five feet either side of centerline, and along the centerline if possible; depth to be approved by the Director of Public Works. Wherever possible, sanitary sewers proposed on existing streets shall consider locating the sanitary sewer main or service outside street right-of-way within separate easements.
C. Gravity Storm and Sanitary Sewer. Gravity sanitary or storm drainage shall have precedent over other systems in planning and installation.
D. Electric Utilities, Power, Telephone, Cable TV. Underground cable and structures for power, telephone and cable TV shall be located on the opposite side of the street from water at a depth of at least 30 inches.
If allowed, overhead cable and utility lines shall be located on poles set back of an existing ditch line or sidewalk, at locations compatible with driveways, intersections, stormwater, and other essential street features. To the extent practical, all overhead utilities shall share facilities so that a minimum of poles are needed and preferably on only one side of street. (Ord. 2007 § 1, 2017; Ord. 1999 § 1 (Exh. 1), 2017. DS § 703)
19.35.040 Installation – New rights-of-way.
A. During New Street Construction. Pole utilities and underground utilities, including service crossings, shall be installed or relocated prior to the start of street construction. Otherwise such utilities, with connections, shall be installed or relocated after the subgrade has been completed but before surfacing has been placed only upon prior approval of the Public Works Director.
B. Within Unmaintained Rights-of-Way. All utility installations inside unmaintained City right-of-way shall be completed under a revocable encroachment permit, approved by the Public Works Director. (Ord. 2007 § 1, 2017; Ord. 1999 § 1 (Exh. 1), 2017. DS § 704)
19.35.050 Installation – Within or adjacent to existing, improved rights-of-way.
A. General. Utility trenching or transverse cuts in City streets shall not be permitted unless it can be shown that alternatives, such as boring or jacking or relocation outside of the paved area, are not feasible, or unless the utility can be installed just prior to reconstruction or overlay of the street.
1. The WSDOT standard specifications (WSDOT Section 7-08, “General Pipe Installation Requirements”) as may be amended shall apply unless otherwise stated below.
2. If trenching or transverse cuts are required within existing and improved rights-of-way, the open cut shall be a neat line made by either saw cutting or jackhammering a continuous line. Saw cutting will be required unless the cut is made prior to reconstruction or an overlay.
3. Temporary pavement patch shall be accomplished by using cold mix (MC 250), ATB or steel plates.
4. Permanent pavement patch shall be as specified in Standard Detail R-10, R-11 and R-11A.
5. Where trench excavation equals or exceeds a depth of four feet, the applicant shall provide, construct, maintain and remove, as required, safety systems that meet the requirements of the Washington Industrial Safety and Health Act, Chapter 49.17 RCW, including Chapter 296-155 WAC. The trench safety systems shall be designed by a qualified person, and meet accepted engineering requirements (see WAC 296-155-660).
6. The developer/contractor shall furnish, install, and operate all necessary equipment to keep excavations above the foundation level free from water during construction, and shall dewater and dispose of the water so as not to cause injury to public or private property or a nuisance to the public. Sufficient pumping equipment in good working condition shall be available at all times for all emergencies, including power outage, and shall have available at all times competent workmen for the operation of the pumping equipment. Water pumped from the trench shall be disposed of using best management practices and shall not be pumped into streams nor to storm drains near streams.
7. Compaction tests will be required to ensure adequate compaction on all lifts. All compaction tests shall be considered by a licensed testing laboratory at the expense of the applicant.
8. Water setting of backfill in trenches is not permitted.
9. The applicant shall expect that all storm and sewer pipes will be inspected for correct bedding materials, correct bedding practices, true invert line and true invert grade. WSDOT Section 7-08.3(2) B on “Pipe Laying” requires “The limit of the variance at the invert shall not exceed plus or minus .03 feet at the time of backfill.”
In addition to visual inspection, expect all storm and sewer pipes to be video inspected. Any sags and/or oval pipes shall be rejected, with no exceptions. In addition, any work conducted without adequate notice of inspection shall be exposed for inspection.
B. Revocable Encroachment Permit Required. No person, firm, or corporation shall commence work or permit any person, firm, or corporation to commence work on the construction, alteration, repair, or removal of any utility or the cutting and/or paving of any street, alley, or other public place in City of Ferndale without first obtaining a revocable encroachment permit, except under emergency conditions when public health safety and welfare is threatened.
C. Curb Cut Relocation or Alteration. For the purpose of protecting the structural integrity of newly constructed roadways, curb cuts installed as a component of a subdivision shall not be altered or relocated within five years of the recording of the subdivision unless it can be demonstrated that the existing curb cut constitutes a risk to life safety. In that case, the applicant and/or contractor performing the work shall be responsible for ensuring that there is no visible impact to the roadway surface or the road’s structural integrity, and shall make all repairs subject to the City’s standard detail drawings, up to a full grind and overlay of the pavement’s surface. (Ord. 2041 § 1, 2018; Ord. 2007 § 1, 2017; Ord. 1999 § 1 (Exh. 1), 2017. DS § 705)
19.35.060 Water distribution systems.
A. Water Distribution System Design Requirements. The City of Ferndale requires water distribution plan submittal for development projects when improvements are proposed within public right-of-way or in easements. Two sets of plans are to be submitted to the Ferndale Department of Public Works for review.
l. Minimum Size Water Mains. The water main sizes for each individual project shall be determined by a professional engineer, but shall not be less than the minimums listed below.
a. Residential Zones. The minimum size water main shall be eight inches in diameter with an average gridded spacing not to exceed 1,500 feet. Pipes less than eight inches in diameter may be allowed by the Public Works Director when future extension is not anticipated, such as in a cul-de-sac, provided the main does not serve a fire hydrant.
b. Commercial, Industrial, and Institutional Zones. All water main construction and reconstruction shall be done pursuant to a design that, when fully implemented, will provide the fire flow requirements of the City of Ferndale’s fire protection and Comprehensive Plan standards. When improvements increase the fire flow requirements, the applicant shall upgrade the water system to support the changes.
The applicant will install, as a minimum, the size pipe as required by the City’s Water Comprehensive Plan. The minimum pressures allowed by the City at any time are 40 psi under instantaneous demand, or 20 psi under maximum instantaneous demand and fire flow combined.
c. Supply Water Mains. Supply water mains shall be provided as specified by the Water Comprehensive Plan. Where clear definition is not provided by the Comprehensive Plan, the minimum size supply main shall be 12 inches in diameter and shall be spaced on approximately 3,000-foot centers. The actual size of the supply main shall be determined by its ability to deliver water based on the peak-daily demand, plus designated fire flow.
2. Valve Spacing. Valves shall be placed on each main at a junction point (node) and shall be spaced along the water main at intervals not to exceed 500 feet for pipe sizes 10 inches in diameter and larger, and not to exceed 800 feet for pipe sizes less than 10 inches in diameter. Resilient seat gate valves shall be used on pipes eight inches in diameter and smaller, and resilient seat butterfly valves used on pipes 10 inches in diameter and larger.
3. Fire Hydrant Spacing. Fire hydrants shall be spaced as follows:
a. No greater than 500-foot intervals along public streets or approved fire access routes for residential areas. Shorter intervals may be required by the Public Works Director due to topography or when a fire hydrant can be made located on an intersection to serve more than one area.
b. No greater than 300-foot intervals along public streets or approved fire access routes for all other areas. Shorter intervals may be required by the Public Works Director.
4. Fire Flow Rates. Supply water mains shall be provided as specified by the Water Comprehensive Plan. All water main construction and reconstruction shall be done pursuant to a design that, when fully implemented, will provide the fire flow requirements of Whatcom County Fire District 7’s fire protection standards and the International Fire Code.
When any improvements which increase the fire flow requirements are made, the water system must be upgraded if necessary to support the changes.
5. Fire Main and Hydrant Standards. All fire hydrants and water mains serving hydrants will be publicly owned and maintained, and shall be located either within the public right-of-way or within an easement granted to the City.
a. Access. An access easement shall be granted to the City and recorded for any public water main on private property. See FMC 19.10.030 for easement descriptions. Fire hydrants must be located within five feet of the required access.
Water mains on private property serving building sprinkler systems will be privately owned and maintained as long as the main serves only one property and no hydrants are required. In this case, the following requirements apply:
i. An approved detector check valve device must be installed;
ii. The City shall own and maintain services up to the detector check valve; the private property owner shall own and maintain services from the detector check valve to their building;
iii. No domestic or other water service allowed on fire main;
iv. No requirement for construction standards imposed by Public Works;
v. No maintenance easement is necessary;
vi. Detector check valve devices must be installed in vault per City of Ferndale Standard Detail W-16 within three feet of main, unless otherwise approved by Director.
b. Materials and Installation. Fire hydrants and fire mains must conform to City of Ferndale Standard Detail W-1 (DOT B-19) and the following standards:
i. Fire hydrants shall have individually valved two two-and-one-half-inch ports and one five-inch main valve opening. A four-and-one-half-inch NST pumper nozzle and a five-inch Storz port with cap and cable shall be supplied. Hydrants shall be M.H. 929T hydrant.
ii. Fire hydrants shall have the Storz port facing the required access and the base flange of the hydrant must not vary more than one foot in elevation from the grade level of the required access. The lowest stem shall be a minimum of 14 inches above the ground.
iii. If, in the opinion of the Public Works Director, fire hydrants are vulnerable to vehicular damage, appropriate crash posts shall be provided. No obstructions shall exist within a five-foot working area of each required access. Crash posts shall be four-inch cement-filled pipe minimum three feet in height with two feet of piping below grade. Hydrant shutoff valves shall be located between five and 20 feet from the hydrant.
iv. Underground supplies to fire hydrants must be inspected. Such inspection shall include visual inspection of piping and hydrostatic pressure test of a minimum of 200 psi or 50 psi in excess of street main pressure, whichever is greater. A flow test will be required when installation is complete.
v. Fire hydrant installation must comply with Standard Detail W-1 (DOT B-19).
vi. Fire hydrants must be maintained in an operable condition at all times and must be repaired or replaced when defective. Hydrants shall be fully operable before construction commences above grade level.
B. Construction of Water Main Extension. The applicant shall contract with a contractor licensed to perform the construction in the state of Washington to install a main extension as approved by the Department of Public Works.
The applicant shall grade all roads to the design subgrade elevation prior to the start of waterline construction and shall advise the City in writing of any changes which may be contemplated during construction. If the applicant changes the subgrade elevation of the road after completion of the waterline extension, or any part thereof, the applicant shall be responsible for all costs incurred for the water extension as a result of said change in subgrade elevation. This obligation shall remain in full force until City releases performance bond or bond of other description in connection with the applicant’s obligation for completion of the roads within the area.
The Department of Public Works shall inspect the installation of the water main to ensure compliance with the specifications. The charges for such inspection, including administrative and overhead charges, shall be withdrawn from the construction inspection fee deposited with the Community Development Director.
At such time as the Director of Public Works determines the remaining funds are not adequate to provide necessary inspection for the project, the petitioner shall be notified and an estimate of additional inspection fees required will be provided.
The additional fees shall be deposited with the Community Development Director prior to the depletion of the funds on deposit. The City reserves the right to reject any installation not inspected and approved by the Department of Public Works. Any monies unexpended from the inspection fee upon completion of the project shall be returned to the petitioner.
Upon satisfactory completion of all required tests and acceptance of the main extension, the Department of Public Works shall cause the extension to be connected to the City system. All costs incurred in the connection, including overhead and administrative charges, shall be paid by the applicant. Any adjustment of the actual cost of installation because of a variance between the estimate and the actual costs shall be refunded upon completion of the job to the petitioner or by payment by the petitioner to the City of any additional expense above the estimate.
When a main extension is to serve a new single-family residential area, individual services shall be installed by the developer to supply each proposed building site. These services shall be installed to City standards. All fees and charges for installation of the services shall be paid pursuant to the City’s fee schedule, and in no case shall be deferred beyond the final inspection of the development.
1. Energizing Main Extensions. No main extensions shall be energized other than for test purposes by duly authorized personnel until the main extension has been accepted by the City and all fees and charges have been paid. If energizing a main is necessary to restore service to existing customers, fire hydrants will not be activated until acceptance of the main extension.
2. Payment for Water Mains. Water mains placed in public rights-of-way or easements and connected to City mains may be paid for by:
a. The party benefiting from the installation;
b. The City;
c. A local improvement district, as provided by law; or
d. Latecomer Agreements. The City may, in accordance with state law, grant the party constructing a new water main the right to partial reimbursement from other abutting property owners benefited by the improvement. Such reimbursement shall be administered by the City and shall be subject to reasonable overhead and administrative charges by the City.
3. Standards for Water Main Construction.
a. Pipe for Water Main. All pipe shall be of AWWA Standards H3-71, C151-71 and cement lining C104-71, and shall be ductile iron, standard thickness Class 50 push-on joints or M.J. joints. The pipe shall be of 150 psi working pressure, plus 100 psi surge pressure.
Pipe laying shall meet the requirements of Section 7-11 of the Washington State Department of Transportation Standard Specifications for Road, Bridge or Municipal Construction. All pipe shall have minimum covering of three feet and a maximum of three and one-half feet unless otherwise approved by the Public Works Director.
b. Fittings. Material for fittings such as crosses, tees, bends, reducers and sleeves shall be ductile iron. Joints shall be M.J., flanged or push-on joints and shall conform to AWWA specifications C-11 0-71 and C-1 04-71.
c. Concrete Thrust Blocking. Concrete blocking shall be as specified in City of Ferndale Standard Detail W-2, or as directed by the Project Engineer. Blocks shall be installed as specified in Section 7-11.3(13) of the Washington State Department of Transportation Standard Specifications for Road, Bridge or Municipal Construction. No precast blocks are allowed.
d. Connection to Existing Water Mains. The contractor must notify the Ferndale Public Works Director of a proposed connection time at least four working days in advance.
e. Hydrostatic Testing and Disinfection of Water Main. All hydrostatic testing and disinfection of water mains shall conform to Sections 7-11.3(11) and 7-11.3(12) of the Washington State Department of Transportation Standard Specifications for Road, Bridge or Municipal Construction, current edition. Hydrostatic testing inspected by City.
f. Water Service Transfers. Tap installations shall meet the requirements of the City of Ferndale Standard Details W Series.
g. Gate Valves. Gate valves shall be for lines two inches through 10 inches, and shall be installed in cast-iron valve boxes. Short-body valves suitable for a non-shock shut-off pressure of 130 psi resilient seat valves and suitable for direct burial are specified.
Gate valves shall be resilient seated iron-body, full-bronze mounted valves conforming to AWWA C509 and suitable for service with the type and class of pipe used.
All valves shall have nonrising stems and shall open counterclockwise and shall be equipped with a two-inch operating nut. Valves will be flange or M.J. joints.
Valve markers shall be located outside of pavement section.
h. Butterfly Valves. Butterfly valves shall be for mains 10 inches and larger and be resilient seated and shall meet or exceed AWWA C504, Class 150B. Butterfly valves shall be suitable for direct burial. Shaft seals shall be standard O-ring seals. The size of the butterfly valves shall be the same as the main on which they are located.
Valves shall be iron-body, full-bronze mounted, resilient-seat valves and suitable for service with the type and class of pipe used.
The valve operator shall be of the traveling-nut or worm-gear type, sealed, gasketed, and permanently lubricated for underground service. The valve operator shall be constructed to the standard of the valve manufacturer to withstand all anticipated operating torques and designed to resist submergence in groundwater.
i. Hydrant Installation. Hydrants shall be supplied and installed according to City of Ferndale Standard Detail W-1 (DOT B-19), and shall include a Storz-type fire hose adapter fitting.
j. Blow-Off Valves. Blow-off valves shall be supplied and installed at high points, line ends, or as required by the plans. Blow-off installation shall be in conformance with Standard Detail W-9 or W-10.
C. Water Service Standards. Water service and sewer service connection fees shall be based on an equivalent residential unit (ERU) basis. Attachment B as set forth in the ordinance codified in Chapter 13.08 FMC gives the basis for calculating single-family connections. The City does not supply flushing water, pool water, or bulk water.
All three-quarter-, one-, and two-inch water services must conform to the following standards and City of Ferndale Standard Detail W-5:
1. Water Service Installation Requirements.
a. Tapping with tapping clamp and saddle must use I.P. Threaded corporations. If the dry-tap method is used, the following minimum hole sizes shall be used:
|
1 7/8" for 2" service |
|
1 5/16" for 1" service |
|
11/16" for 3/4" service |
Caution, care, and prudence are necessary in aligning the clamp and saddle to assure full flow capability.
b. Corporation taps shall make as nearly as possible a 45-degree angle off the vertical centerline of the main. No tap is to be made on the top of a water main.
c. Type “K” copper shall be used on water services within the public right-of-way.
d. Curb stops shall be located as per subsection (C)(2)(b) of this section.
e. All underground fittings shall be flared within the public right-of-way, no sweat or compression connections are to be used. The use of Teflon tape as a sealant is acceptable, but the use of pipe dope is not acceptable.
f. The water service pipe shall have a minimum of 24-inch depth and a maximum of 36-inch depth, including under ditch sections. If a meter is required, there shall be 30 inches cover in the meter area.
All meters and meter installations shall meet City of Ferndale Standard Detail W-5. If developer changes ground elevation after completion of water service installation, developer is responsible for all costs incurred as a result of said changes.
g. No service is to be covered until the City Inspector has inspected the initial installation. Note that all corporations must be in an ON position and all curb stops must be in the OFF position.
h. Service testing shall be done in conjunction with water main testing. Any air relief and flushing shall be the responsibility of the developer.
i. An acceptance inspection will be made by the City upon completion of all project work. During inspection, every service shall be turned on to its full capacity to check flow and guarantee that each service line has been flushed. In no case shall the acceptance inspection be made until all project work is complete. Damage incurred during other construction work on the project shall be corrected by the developer or his agent prior to acceptance by the City.
j. The bond release inspection shall be made prior to the end of the two-year maintenance bond period. Any problems noted at this time shall be corrected by the developer and/or bonding company prior to releasing the bond.
k. Staking of lots and/or property lines to assure correct water service locations is the responsibility of the developer. Locations are to be as shown on the approved drawings. Errors due to failure to provide a property survey or due to changing lot locations during final plat approval shall be corrected by the developer at the time of such change or when the error is detected by the City.
l. Tools, materials and work area shall be maintained in a sanitary condition at all times.
2. Water Service Meter Box Installation Requirements.
a. Cover of 24 to 30 inches shall be maintained from finished grade to the service pipe except where a variance is approved by the Department of Public Works. Note that the top of the box shall be flush with the finished grade and that this includes the expansion material when required.
b. The meter setter or curb stop shall be located within the meter box.
i. Minimum clearance of one inch from inside surface.
ii. Maximum clearance of two inches from inside surface shall be maintained from the stop.
iii. Stops shall be just before the setter inside the meter box within the public right-of-way or as approved by the City. In those situations where the stop will not be located within the meter box, an additional box must be installed for the stop.
c. Meter boxes shall conform to City of Ferndale Standard Details W-6 through W-8. High density polyethylene (HDPE) boxes shall be used when located within the travel way or on gravel.
d. Location of Meter Boxes.
i. If a meter box for a three-quarter-inch or one-inch service is to be located within a sidewalk area, Standard Details W-6 through W-8 must be used.
ii. An expansion material must be used around the lid section to enable removal for maintenance. The material shall be flush with the lid section to avoid any cracks or protrusions.
iii. As-builts shall show location of water service taps into main, location of meter/boxes with distances to the right-of-way or nearest property corners.
e. All domestic water services require an in-line pressure reducing valve (PRV). PRVs will be located in an accessible area within the structure. Inspection of the device and location will be performed by the Building Department prior to final occupancy. (Ord. 2059 § 1 (Att. A), 2018; Ord. 2048 § 1 (Att. A), 2018; Ord. 2007 § 1, 2017; Ord. 1999 § 1 (Exh. 1), 2017. DS § 706)
19.35.070 Sanitary sewer systems.
The City of Ferndale requires sanitary sewer construction plan submittal on development projects when improvements are proposed within public right-of-way or an easement. This section has been developed to assist in preparation of sewer construction plans. It includes items pertinent for the City’s review and reflects established professional civil engineering practice for preparation of construction plans. Two sets of plans must be submitted to the Public Works Department for initial review.
Sewer systems shall be designed to the requirements set forth in the most current edition of Criteria for Sewage Works Design published by the Washington State Department of Ecology, excepting requirements set forth in these standards.
A. Criteria for Sewage Design. This section serves as a guide for the design of sewage collection systems for the City of Ferndale. The goals are:
• To ensure that the design of sewage collection systems is consistent with public health and water quality objectives of the state of Washington.
• To establish a basis for the design and review of plans and specifications for sewage systems.
• To assist the owner or the owner’s authorized engineer in the preparation of plans, specifications, reports, and other data.
• To guide departments in their determination of whether an approval, permit, and/or a certificate for a sewage system should be issued.
1. Design. Sewer systems shall be designed and constructed to achieve total containment of sanitary wastes and maximum exclusion of infiltration and inflow. No new combined stormwater and sanitary sewers will be allowed.
a. Overflows. No overflows in separate sewers or new overflows in existing combined sewers shall be permitted.
b. Calculations. Computations and other data used for design of the sewer system shall be submitted to the Department upon request.
2. Design Consideration.
a. Design Period. Collection sewers should be designed for the ultimate development of the tributary areas. Selection of the design period for trunk and interceptor sewers should be based on evaluation of economic, functional, and other considerations, such as:
i. Possible solids deposition, odor, and pipe corrosion that might occur at initial flows.
ii. Population and economic growth projections and the accuracy of the projections.
iii. Comparative costs of staged construction alternatives.
iv. Effect of sewer sizing on land use and development.
b. Design Flows. New sewer systems shall be designed on the basis of per capita flows or alternative methods. Documentation of the alternative method shall be provided upon request. Design flows shall be based upon equivalent residential units (ERUs), as contained within Attachment B to the ordinance codified in Chapter 13.20 FMC. The City may require that the applicant install a sewer meter to verify the operational volume of a development when it is anticipated that the volume of water use and sewer flows measurably different.
These figures are assumed to cover normal infiltration, but an additional allowance should be made where conditions are unfavorable. If there is an existing water system in the area, water consumption figures can be used to help substantiate the selected per capita flow. Generally, the sewers should be designed to carry, when running full, not less than the following:
i. Lateral and Submains. “Minimum peak” design flow should be not less than 400 percent of the average. “Lateral” is defined as a sewer that has no other common sewers discharging into it. “Submain” is defined as a sewer that receives flow from one or more lateral sewers.
ii. Main, Trunk, and Interceptor Sewers. “Minimum peak” design flow should be not less than 250 percent of the average design flow. “Main” or “trunk” is defined as a sewer that receives flow from one or more submains. “Interceptor” is defined as a sewer that receives flow from a number of main or trunk sewers, force mains, etc. An alternate method for trunk sewers is to use 80 gallons per capita, per day, a peaking factor from
Table 6-1 subject to the above limits, and 1,209 gallons per acre, per day, for infiltration and inflow.
New sewer systems may be designed by alternative methods other than on the basis of per capita flow rates. Alternative methods may include the use of peaking factors for the contributing area, allowances for future commercial and industrial areas, separation of infiltration and inflow from the normal sanitary flow, and modification of per capita flow rates (based on specific data). Documentation of the alternative method used shall be provided upon request.
c. Design Factors. The following factors must be considered in the design of sanitary sewers:
i. Peak sewage flows from residential, commercial, institutional, and industrial sources;
ii. Groundwater infiltration;
iii. Topography and depth of excavation;
iv. Treatment plant location;
v. Soil condition;
vi. Pumping requirements;
vii. Maintenance;
viii. Existing sewers;
ix. Existing and future surface improvements;
x. Controlling service connection elevations;
xi. Easements (see Chapter 19.10 FMC).
d. Design Considerations. The utility shall be extended through the property to allow for future extension, expansion and construction of City’s collection system or for conformance with Comprehensive Sewer System Plan.
3. Design and Construction Details.
a. Gravity Sewers.
i. Minimum Size. No sewer shall be less than eight inches in diameter.
ii. Depth. In general, sewers should be a minimum of three feet deep to prevent freezing and physical damage and should receive sewage from existing dwellings by gravity.
iii. Roughness Coefficient. An “n” value of 0.013 shall be used in Manning’s formula for the design of all sewer, facilities (regardless of pipe material) except inverted siphons, where an “n” value of up to 0.015 can be used.
iv. Slope. All sewers shall be designed and constructed to give mean velocities, when flowing full, of not less than 2.0 feet per second. The following minimum slopes shall be provided; however, slopes greater than these are desirable:
|
Sewer Size (inches) |
Minimum Slope (feet per 100 feet) |
|---|---|
|
8" |
0.40 |
|
10" |
0.28 |
|
12" |
0.22 |
|
15" |
0.15 |
Under special conditions, slopes slightly less than those required for the 2.0 feet per second velocity when flowing full may be permitted. Such decreased slopes will only be considered where the depth of flow will be 0.3 of the diameter or greater for design average flow. Whenever such decreased slopes are proposed, the design engineer shall furnish computations of the depths of flow in such pipes at minimum, average, and daily or hourly rates of flow. The City must recognize and accept in writing the problems of additional maintenance caused by decreased slopes.
Sewers shall be laid with uniform slope between manholes.
Sewers on 20 percent slope or greater shall be anchored securely with concrete anchors or equal. Suggested minimum anchorage spacing is as follows:
(A) Not over 36 feet center-to-center on grades from 20 to 35 percent.
(B) Not over 24 feet center-to-center on grades from 35 to 50 percent.
(C) Not over 16 feet center-to-center on grades 50 percent or greater.
v. Alignment. Gravity sewers 24 inches or less in diameter shall be designed with straight alignment between manholes. Curved sewers may be approved, where circumstances warrant, for sewers greater than 24 inches in diameter.
vi. Matching Pipe. Where a smaller sewer joins a larger one, the invert of the larger sewer shall be lowered sufficiently to maintain the same energy gradient. An approximate method for securing these results is to place the 0.8 depth point of both sewers at the same elevation.
vii. High-Velocity Protection. The use of ductile-iron pipe is required where velocities greater than 15 feet per second are expected.
viii. Material. Any generally accepted material for sewers will be given consideration, but the material selected should be adapted to local conditions, such as characteristics of industrial wastes, possibility of septicity, soil characteristics, exceptionally heavy external loadings, abrasion, and similar problems.
Material and installation specifications for all pipe, except cleanouts, shall conform to the Standard Specifications, current edition. Cleanouts shall be according to City of Ferndale Standard Detail SS-5 (DOT B-18b). Unless otherwise stated, all materials specifications shall conform to the Standard Specifications, current edition. Requirements shall be set forth in the specifications for the pipe and methods of bedding and backfilling so as not to damage the pipe or its joints, impede cleaning operations and future tapping, nor create excessive side fill pressure or ovulation of the pipe, nor seriously impair flow capacity.
All sewers shall be designed to prevent damage from superimposed loads. Proper allowance for loads on the sewer shall be made based on the width or depth of trench. When standard-strength sewer pipe is not sufficient, the additional strength needed may be obtained by using extra-strength pipe or by special construction, such as improving bedding conditions or encasing the pipe in concrete. When extra-strength pipe is required, the design criteria (loading requirements, soil strengths, etc.) shall be supplied to the City.
ix. Connection to Existing Sewer Main. When a sewer service or main must be connected to an existing sewer main, installation shall conform to City of Ferndale Standard Detail SS-14.
x. Specifications for Sewer Pipe. The following specifications are to be used in conjunction with the Standard Specifications for Road, Bridge, and Municipal Construction.
Material to be used for bedding of these flexible conduits shall conform to materials listed in WSDOT standard specifications. No bedding material shall be used unless accepted by the Public Works Director. Samples shall be submitted by the contractor at least 72 hours in advance of its intended use to enable it to be inspected and tested.
Bedding shall be placed in more than one lift as shown in Standard Detail SS-1 (DOT B-18c). The first lift to provide at least four-inch thickness under any portion of the pipe (six inches in the case of solid rock excavation) to be placed before the pipe is installed. This bedding layer shall extend the full width of the trench bottom to the specified thickness after being consolidated by the use of a “flat tamper.” This lift shall be spread smoothly and bell holes dug where necessary to ensure uniform support along the full length of the pipe barrel.
Subsequent lifts of not more than six inches shall be placed up to the spring line of the pipe. These lifts shall be consolidated first by the use of tamping bars, taking care to work the material under the pipe haunches so that no voids are left, then a flat tamping bar shall be used to compact the bedding material along the side of the pipe to the trench walls to provide lateral support for the pipe. These lifts shall be individually compacted to 90 percent density, as determined by ASTM 0698, Method “D.”
Further lifts of moderately compacted bedding material shall be placed, not more than six inches thickness to a minimum of eight inches, above the crown of the pipe (a minimum of 12 inches above the crown of pipe where rock is encountered in trench excavation).
xi. Bank-Run Gravel for Trench Backfill. Whenever a trench is excavated in the existing or newly paved roadway, sidewalk or other areas where minor settlement would be detrimental, the entire trench shall be backfilled with bank-run gravel, Class “B,” and compacted to a 95 percent density as defined by ASTM D-1556. Selected native materials may be used for trench backfill in other areas if approved by the Public Works Director. See Standard Detail SS-16.
(A) Unsuitable backfill material shall be removed from the site and hauled to an approved disposal site. The Public Works Director shall be provided with the location of all disposal sites to be used, as well as copies of the permits and approvals for such disposal sites.
xii. Joints and Infiltration. The method of making joints and materials used shall be included in the specifications. Leakage tests shall be according to Washington State Department of Transportation Standard Specifications for Road, Bridge and Municipal Construction SE-7-17.3(4)F for non-air-permeable materials and SE-7-17.3(4)D for air-permeable materials.
The use of television camera or other visual methods of inspection prior to placing the sewer in service is required.
b. Pressure Systems. Pressure sewer systems are considered developmental technology. All pressure systems will be designed by a professional engineer and will be judged on a case-by-case basis.
c. Manholes. Manholes shall conform to City of Ferndale Standard Details SS-3, SS-3A and SS-4 (DOT B-23c).
Manholes shall be installed at the end of each line of eight-inch diameter or greater unless the eight-inch line is expected to be extended in the foreseeable future, in which case a cleanout shall be installed at the end of the line; at all changes in grade, size, or alignment; at all intersections; and at distances not greater than 400 feet for sewers 15 inches or less and 500 feet for sewers 18 inches to 30 inches. Cleanouts may be used in lieu of manholes at the end of lines eight inches in diameter and not more than 150 feet long if they are accessible to the City’s maintenance equipment. Cleanouts shall conform to City of Ferndale Standard Detail SS-5 (DOT B-18b).
Drop manholes shall conform in all respects to City of Ferndale Standard Details SS-10 and SS-11. An outside drop connection shall be provided for a sewer entering a manhole at an elevation of 24 inches or more above the manhole invert. Where the difference in elevation between the incoming sewer and the manhole invert is less than 24 inches, the invert shall be filleted to prevent solids deposition.
The minimum diameter of manholes shall be 48 inches, although larger diameters are preferable. The minimum clear opening in the manhole frame shall be 23 inches. Manholes connecting significant industries to the system should be larger, to provide space for monitoring and sampling equipment.
Flow channels in manholes shall be of such shape and slope to provide a smooth transition between inlet and outlet sewers and to minimize turbulence. Channeling height shall be to the crowns of the sewers. Benches shall be sloped from the manhole wall toward the channel to prevent accumulation of solids.
Watertight manhole covers shall be used wherever the manhole tops may be flooded. Manholes of brick or segmented block shall be waterproofed on the exterior with plaster coatings, supplemented by a bituminous waterproof coating where groundwater conditions are unfavorable.
Direct-line connections to the manholes or to short stubs integral with the manholes shall be made with flexible joints. Flexible joints are those which permit the manholes to settle without destroying the watertight integrity of the line connections.
Ventilation of gravity sewer systems should be considered where continuous watertight sections greater than 1,000 feet in length are incurred.
Frames and covers shall conform to the current City of Ferndale Standard Detail SS-10. Frames and covers of aluminum material will be allowed if approved by the Public Works Director.
All covers located in an easement or constructed of aluminum material shall be the locking type.
Materials used for manhole steps shall be highly corrosion resistant. The use of galvanized steel should be avoided. Manhole steps and ladders shall conform to Standard Details SS-3 and SS-3A.
4. Special Details.
a. Protection of Water Supplies. There shall not be a physical connection between a public or private potable water supply system and a sewer, or appurtenance thereto, which would permit the passage of any sewage or polluted water into the potable supply.
No sewer shall be constructed within 100 feet of a potable water supply well or other potable water source or structure without approval of the City and the Washington State Department of Health.
Relation to water mains shall be as follows:
i. Horizontal Separation. Whenever possible, sewers should be laid at least 10 feet, horizontally, from any existing or proposed water main. Should local conditions prevent a lateral separation of 10 feet, a sewer may be laid closer than 10 feet to a water main if the sewer is constructed of cast-iron or ductile-iron pipe with watertight joints, and:
(A) It is laid in a separate trench; or
(B) It is laid in the same trench with the water main located at one side on a bench or undisturbed earth.
In either case, the elevation of the crown of the sewer is at least 18 inches below the invert of the water main and in no case will the sewer be separated horizontally from the water main less than four feet.
ii. Vertical Separation. Whenever sewers must cross under water mains, the sewer shall be laid at such an elevation that the top of the sewer is at least 18 inches below the bottom of the water main.
When the elevation of the sewer cannot be buried to meet the above requirements, the water main shall be relocated to provide this separation or the sewer constructed with slip-on or mechanical-joint cast-iron pipe, or pre-stressed-concrete cylinder pipe for a distance of 10 feet on each side of the water main. One full pipe length of water main shall be centered over the sewer so that both joints will be as far from the sewer as possible.
b. Easements. Any sewer lines located within an easement shall be properly dedicated to the City of Ferndale and recorded per Chapter 19.10 FMC. Access roads to manholes on easements shall be per FMC 19.10.030.
c. Stream Crossings. Sewers entering or crossing streams shall not be proposed unless there is no other practical alternative. If construction is allowed, sewer lines must be constructed of watertight pipe. The pipe and joints shall be tested in place, shall exhibit “0” infiltration, and shall be designed, constructed, and protected against anticipated hydraulic and physical, longitudinal, vertical, and horizontal loads, erosion, and impact. Sewers laid on piers across ravines or streams shall be allowed only when it can be demonstrated that no other practical alternative exists. Such sewers on piers shall be constructed in accordance with the requirements for sewers entering or crossing under streams. Construction methods and materials shall be such that sewers will remain watertight and free from change in alignment or grade.
Permits from other agencies or departments are required for work in or adjacent to waterways.
Inverted siphons shall have not less than two barrels with a minimum pipe size of six inches, and shall be provided with necessary appurtenances for convenient flushing and maintenance. The manholes shall be designed to facilitate cleaning, and, in general, sufficient head shall be provided and pipe size selected to secure velocities of at least 3.0 feet per second for average flows. A rock catcher and coarse screen shall be provided to prevent plugging of the siphons. The inlet and outlet details shall be arranged so that normal flow can be diverted to one barrel and so that either barrel may be removed from service for cleaning or other maintenance.
d. Side Sewer Installation. Four- or six-inch side sewer installations and as-builts shall conform to City of Ferndale Standard Details SS-6 through SS-8. For new sewer main construction, four- or six-inch tees shall be placed on sewer mains as shown on plans or as the Public Works Director designates. Double services shall conform to City of Ferndale Standard Detail SS-13.
e. As-Built Information Required. Location of manholes, cleanouts, inverts, side sewer saddles on sewer main, side sewer ends with distances to the right-of-way, property corners and depths. (Ord. 2007 § 1, 2017; Ord. 1999 § 1 (Exh. 1), 2017. DS § 707)
19.35.080 Street illumination.
A. Requirements.
1. Continuous illumination will be required for channelization accommodating additional lanes including the tapers. Additional illumination will also be required at intersections and designated crosswalks. When two streets of different designations intersect, the lighting shall be one and one-half times the illumination required on the more highly illuminated street.
2. Street illumination shall require LED luminaires.
3. The design for street lighting systems shall conform to the Illuminating Engineering Society of North American (IES) Standards Specification for Roadway Lighting. Puget Sound Energy (PSE) and its subsidiary IntoLight owns and maintains the street illumination system for the City of Ferndale.
4. Plats and Short Plats, Commercial, Industrial or Institutional Property Development.
a. Street lighting is required for all public streets. The street lighting design shall be approved by the Public Works Director prior to approval of civil infrastructure plans. The cost of all street lighting shall be paid for by the developer. See Table 7-4 for minimum illumination requirements.
b. The City will accept maintenance and power cost responsibility for the public street light system when 50 percent of the lots within a plat have been developed. For the purposes of this section, “developed” shall mean that a final inspection has been completed on the primary residential structure. Until this threshold has been crossed, the developer is responsible for the maintenance and energy charges for the street lighting system.
c. Street lighting is required on private streets within a plat, though not required for private driveways serving less than six residential units. See Table 7-4 for minimum illumination requirements. The City does not install or maintain private street lighting systems.
i. On private streets, all street light maintenance and power costs shall be paid by the developer, homeowner, or homeowner’s association.
5. Existing Residential Areas. If a resident or group of residents desires the installation of a new street light, they may make a request in writing to the Public Works Director.
a. When evaluating the request, the Public Works Director shall first evaluate whether existing or proposed conditions represent a risk to life or safety. The Public Works Director may also evaluate the costs of installation and maintenance, the location of existing utilities, whether the light would obstruct traffic or create unnecessary and avoidable impacts on adjacent properties, and other factors.
6. Commercial. Street lighting is required on all public street frontages and shall be compatible with required landscaping as described by Chapter 18.74 FMC. The developer is responsible for design, installation or relocation of new or existing lighting. Commercial development shall replace existing lighting systems on power poles with a new lighting system serviced by underground power if the system will not conflict with essential distribution lines.
a. When a project is proposed within an area featuring decorative street lighting, the developer shall be required to match the decorative street lighting when replacing existing lights. When no suitable match exists, the developer shall work with the City and PSE to identify a suitable match.
7. The City of Ferndale is responsible for designating the street classification.
8. PSE/IntoLight will design, engineer, provide, install, own and maintain the lighting system for the benefit of the City of Ferndale.
B. Ownership and Maintenance.
1. Under franchise with the City, Puget Sound Energy (PSE) provides, installs, owns and maintains the street illumination system for the City. Maintenance of the completed lighting system is provided by Puget Sound Energy.
2. The property owner or homeowner’s association shall maintain private lighting systems.
C. General Considerations.
1. Existing street lighting systems that extend along the frontage of a new development project, or within the limits of a roadway improvement project, will not generally be required to be brought into conformance with these street lighting standards, unless the project is required to install full or three-quarter road frontage improvements. If the City determines that the existing street light systems should be brought into conformance with these requirements due to special circumstances, the applicant will be notified of this requirement during the City’s development review process.
2. When required, the applicant is responsible for the installation of street lights and all accessories necessary to energize the street light system consistent with these standards.
3. For all new street light installations, the applicant shall coordinate jointly with Puget Sound Energy and the Public Works Department to prepare a street lighting plan for submittal to and approval by the Public Works Director. The type of installation shall be as set forth in PSE (IES) standard specifications and these standards. The applicant may request that PSE design the street illumination system.
4. Street lighting plans shall be designed and submitted to the Public Works Director for review and approval prior to construction. All lighting plans shall be prepared by a licensed engineer experienced with lighting design or by PSE (IntoLight Lighting Services). Lighting plans shall be established pursuant to PSE (IES) standard specifications and these standards.
5. The applicant shall coordinate with Puget Sound Energy for the availability and location of power sources for the new lighting system.
6. All public street lighting systems shall be accessible for public maintenance by a wheeled vehicle weighing 20,000 pounds.
7. All street light installations including wiring, conduit and power connections shall be located underground. Exception: Residential areas with existing above-ground utilities may have street lighting installed on the existing power poles. The applicant will be responsible for providing or obtaining necessary easements for underground power for street lighting systems designed and constructed as part of an approved development permit.
8. As-built drawings must be submitted to the Public Works Director pursuant to FMC 19.05.130 prior to receiving a final occupancy permit.
9. Street light circuitry will be provided with available voltage.
10. The exact location of the power source should be indicated. System continuity and extension should be considered.
11. Particular attention shall be given to locating luminaires near intersections, at all street ends, and at pedestrian crossings.
D. Design Standards.
1. Illumination. Calculations should include luminaire spacing, illumination level, uniformity ratio, line losses, power source and other necessary details for the electrical and physical installation of the street lighting system.
2. Illumination Levels Using Cut-Off Luminaires. Street light illumination levels shall conform to the levels listed in the table below:
|
Road Class |
Area Class |
|
|---|---|---|
|
Residential |
Industrial/Commercial |
|
|
Private (Access) |
0.6 |
N/A |
|
Residential (Local Access) |
0.4 |
0.9 To 1.2 |
|
Residential (Collector) |
0.6 |
0.9 To 1.2 |
|
Arterial* |
0.8 |
1.2 To 1.6 |
|
|
|
*Intersection lighting is required. Street lights shall be placed in accordance with the standards listed below. |
Uniformity Ratio:
|
6:1 average to minimum for private (access) |
|
6:1 average to minimum for residential (local access) |
|
4:1 average to minimum for residential (collector) |
|
3:1 average to minimum for arterial |
Average illumination levels at intersections shall be one and one-half times the illumination required on the more highly illuminated street. Exception: Local residential streets intersecting other local residential streets shall not require one and one-half times the illumination at other intersections; provided, that one luminaire is placed at the intersection.
At signalized intersections, all signal poles shall include a street light. Lighting levels at these locations may be higher than the criteria listed above.
3. Luminaires shall be cut-off and shall be LED color temperature 4000k.
*Note: LEDs will be used by the City as an alternative to reduce energy and maintenance cost.
4. Light Standards.
a. Light standards shall be located on one side of the roadway only or shall be located opposite each other when placed along both sides of the roadway.
b. Staggered spacing will be allowed upon approval of the Public Works Director where there is an established staggered pattern and it is necessary to continue this pattern, or when site or safety conditions prevent locating luminaires on only one side of the roadway.
i. Preservation or creation of view shall not be a primary consideration when placing or relocating poles.
c. In areas where the street width differs from the City standard, or there are other factors influencing the location of the street lights, the Public Works Director will provide input to the applicant on acceptable options.
d. Street light poles shall be direct buried as specified by PSE. Line loss calculations shall show that no more than a five percent voltage drop occurs in any circuits. Branch circuits shall serve a minimum of four luminaires.
5. Conductors. Conductor size will be determined by the wattage and circuit lengths provided through the IES design. The minimum wire size for any illumination circuit shall be No. 6 aluminum. No. 10 wire will be acceptable for the pole and bracket cable within the light standard only.
Illumination plan requirements and design criteria are listed below.
a. Street lighting is required on all public and private streets, with the exception of private driveways.
b. The applicant shall consult with the City of Ferndale to determine if decorative street lighting is required, and if so shall conform to the adopted lighting standard.
c. Any nonconforming street lighting that must be removed as part of construction activities shall be replaced with conforming street lighting. (Ord. 2007 § 1, 2017; Ord. 1999 § 1 (Exh. 1), 2017. DS § 708)