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Chapter 4: sewer design requirements

ENGINEERING DESIGN MANUAL

October 28, 2009


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CITY OF ENCINITAS ENGINEERING DESIGN MANUAL - 2009

Table of Contents Page i

Table of Contents

CHAPTER 4 SEWER DESIGN REQUIREMENTS

Subject Section Page

GENERAL INFORMATION 4.100 4-1

Definitions, Abbreviations, and Terminology 4.101 4-1

Statutes and Requirements 4.102 4-3

SEWER STUDY AND SEWER FLOWS 4.200 4-5

General Sewer Flow Considerations 4.201 4-5

Tributary Area 4.201.1 4-6

Estimation of Ultimate Population 4.201.2 4-6

Ultimate Land Use 4.201.3 4-6

Flow Types 4.201.4 4-7

Major Point Source Discharges 4.201.5 4-7

Inflow and Ground Water Infiltration 4.201.6 4-7

Sewer Flow Calculations 4.202 4-7

Peaking Factor 4.202.1 4-8

Flow Contributions from Residential Populations 4.202.2 4-8

Flow Contributions from Non-Residential Uses 4.202.3 4-8

Sewer Flow Table 4.202.4 4-9

SEWER SIZING AND MINIMUM REQUIREMENTS 4.300 4-10

Sewer Depth of Flow Requirements 4.301 4-10

General Sewer Design Criteria 4.302 4-10

Sewer Main Extensions and Connections to the Sewer 4.303 4-13

Requirement for Connection to Sanitary Sewer 4.303.1 4-13Requirement for Separate Sewer Laterals 4.303.2 4-14

Pumped Sewer Laterals 4.303.3 4-15

Permits for Construction of a Sewer Lateral 4.303.4 4-15

Construction Requirements for Sewer Laterals 4.303.5 4-16

Grease/Oil/Sand Interceptors 4.303.6 4-17


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Table of Contents

CHAPTER 4 CONTINUED

Subject Section Page

SEWER AND ACCESS EASEMENTS 4.400 4-19

Unauthorized Sewer Connection and Unauthorized 4.303.7 4-17Sewer DischargeSewer Easement Required 4.401 4-19

Sewer Access Easement Required 4.402 4-19

Requirements for Access Road 4.402.1 4-19

Considerations for Sewer Easement Location and Width 4.403 4-20

Shared Sewer Easements 4.403.1 4-20

Sewer Within Private Street 4.403.2 4-21Granting of Sewer Easements 4.403.3 4-21

SEWER IMPROVEMENT PLANS AND PERMI TS 4.500 4-22

SEWER REIMBURSEMENT DISTRICTS 4.600 4-23

General Information 4.601 4-23

Administration of Reimbursement Agreements 4.602 4-23

Properties Included in the Reimbursement District 4.603 4-25

Calculation of the Reimbursement Fee 4.604 4-26


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Chapter 4 page 4-1

CHAPTER 4

SEWER DESIGN REQUIREMENTS.

4.100 GENERAL INFORMATION.

The City Engineering Department reviews and approvesdesigns for sewer improvements. The intent of thischapter is to describe City of Encinitas sanitary sewerdesign criteria and permitting. Sanitary sewer modelingand design requirements are discussed in Sections 4.200and 4.300 below. Information on sewer easements,permits, and sewer reimbursement districts is presented inSections 4.400, 4.500, and 4.600 respectively.

The City of Encinitas is served by three sewer agencies:Cardiff Sanitation District (CSD), Encinitas Sanitary District(ESD), and Leucadia Wastewater District (LWD). TheCardiff Sanitation and Encinitas Sanitary Districts are nowadministered by the City, but billing and fees remaindifferent for the two districts. Leucadia WastewaterDistrict is a separate agency from the City and must becontacted separately for that districts requirements. The

requirements discussed herein pertain only to the districtsadministered by the City, CSD and ESD. A map of theareas included in each of the three sewer districts isincluded as Appendix 4.8 of this manual.

Because of the unique nature of each sewer project, theinformation presented here is intended as a guideline forthe minimum requirements of the City of Encinitas; morestringent requirements may be applied. Deviations fromthe criteria herein will be allowed with advance written

approval by the City Engineer.

4.101 DEFI NI TI ONS, ABBREVI ATI ONS, AND TERMI NOLOGY.

Certain words and phrases used in this manual are definedas set forth below. All definitions provided in the City ofEncinitas Municipal Code shall also be applicable to this


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manual, and said definitions are hereby incorporated bythis reference.

A. ADWF: shall be used as an abbreviation for AverageDry Weather Flows.

B. CFS: shall be used as an abbreviation for Cubic Feetper Second.

C. CSD: shall be used as an abbreviation for CardiffSanitation District.

D.EDU: is used as an abbreviation for EquivalentDwelling Unit. EDUs are used as a method forconverting various kinds of sewer usages to anequivalent multiple of residential dwelling unit usage.

E. ESD: shall be used as an abbreviation for EncinitasSanitary District.

F. Infiltration: shall mean the total extraneous flowentering a sewer system, excluding sanitary sewage,because of poor construction, corrosion of the pipe,ground movement or structural failure through joints,porous walls or breaks.

G. Inflow: shall mean the extraneous flow which enters asanitary sewer from sources other than infiltration, suchas roof drains, basement drains, land drains or manholecovers.

H. Interceptor Sewer: shall be used to mean a publiclymaintained sewer ranging from 10 to 30 inches indiameter and which collects the sewage from publicsewer mains and conducts such sewage to a sewertrunk or point of treatment.

I. LWD: shall be used as an abbreviation for LeucadiaWastewater District.

J. PDWF: shall be used as an abbreviation for Peak DryWeather Flows.


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K. Private Sewer: shall mean any sewer serving morethan one property, not lying within any public sewereasement or right-of-way, and not maintained by theCity.

L. Public Sewer: shall be used to mean any sewer, otherthan a sewer lateral, which has been constructed in apublic street, alley, or other public right-of-way, or in apublic sewer easement, and is proposed to be a part ofthe sewer system publicly maintained by the City.

M. Outfall Sewer: shall mean a major sewer that receivestreated wastewater from a treatment plant and carriesflows to a point of disposal.

N. Sewer Lateral: shall mean a sewer pipe conveyingwastewater from the private connection point to thepublic sewer main or private sewer. The privateproperty owner is entirely responsible for the repair andmaintenance of the entire sewer lateral serving his orher property. Permits are required for any work withinpublic rights-of-way or easements.

O. Sewer Main: shall be used to mean a publiclymaintained sewer pipe to which sewer laterals are joined. The term sewer main shall be used herein to

describe requirements pertaining to sewers generally;the terms interceptor sewer and trunk sewer shallbe used when the requirements for larger sewer pipesdiffer from those for the typical 8-inch sewer main.

P. SFR: shall be used as an abbreviation for Single FamilyResidence.

Q. Trunk Sewer: shall be used to mean a publiclymaintained sewer pipe 30 inches or more in diameter

and having tributary sewer mains and interceptors.

4.102 STATUTES AND REQUI REMENTS.

Sewer designs and plans shall conform to all of thefollowing:

A. City of Encinitas Municipal Code.


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B. Requirements as specified in the associated Conditionsof Approval, if any.

C. County of San Diego Regional Standard Drawings.

D. Standard Specifications for Public Works Construction(Greenbook) specifications.

E. Requirements and guidelines as specified in thismanual.

F. Staff Policies.G. Generally accepted engineering principles and practices.

H. State of California Department of Health Servicesspecifications.


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4.200 SEWER STUDY AND SEWER FLOWS.

A sewer study may be required at the discretion of the CityEngineer when a proposed development intensifies landuse from the existing condition, when the project has the

potential to generate additional sewer flow, when theexisting sewer infrastructure is insufficient to support theproject, or when the sewer infrastructure is prone tofailure due to the inadequacy of a portion of the sewersystem.

The sewer study shall address:

A. The existing condition, in order to identify existingdeficiencies in the system;

B. The condition with the proposed development, in orderto identify additional deficiencies created by theproposed development; and

C. The General Plan ultimate land use condition, in orderto identify the ultimate pipe size required for theultimate improvements and condition.

The sewer study shall be submitted to the EngineeringDepartment for review and approval. Most often, projectsrequired by the Engineering Department to perform astudy shall satisfactorily complete the study prior to theissuance of any discretionary permits for the project. Thesewer study shall follow the methodology outlined in thischapter. If computer models are utilized to prepare thesewer study, the program name together with a briefdescription of the methodology, organization of the outputdata, and input parameters used in the program shall beprovided to the City Engineer.

4.201 GENERAL SEWER FLOW CONSI DERATI ONS.

Each service area will have unique characteristics whichmay preclude the use of a uniform approach to sewer flowcalculations. However, the information presented in thismanual shall be used for the preparation of the sewer flow


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calculations unless a more detailed analysis is authorizedby the City Engineer.

The following criteria shall be evaluated to projectwastewater flows; each is discussed in greater detail later

in this section.

A. Tributary Areas.B. Estimation of Ultimate Population.C. Ultimate Land Use.D. Flow Types.

1. Per-capita Flows2. Residential Flows3. Commercial Flows4. Industrial flows

E. Major Point Source Discharges.F. Inflow and Ground Water Infiltration.

4.201.1 Tributary Area. The tributary area of a sewer shall includeall areas that will contribute to the flow in the sewersystem, including flows from the ultimately developedservice area and basin to basin flow routings. Tributaryareas may be limited by topography as well as natural orhuman-made boundaries. Flows to the point of connectionat the main line shall be estimated and included. The

boundaries of the tributary area used in the sewer designshall be submitted to the City on a plat also showing thetopography of the area, any existing sewer facilities, andexisting or proposed sewer connections.

4.201.2 Estimation of Ultimate Population. The population of thetributary area is the basis for the sewer design flowcalculations. The population estimate shall be based uponthe proposed development and the ultimate land use for

the service area. The population shall be estimated asaccurately as possible using the most recent information.

4.201.3 Ultimate Land Use. The type of land use defines both thepopulation densities and the type of contributors within theareas tributary to the sewer. Land use considerations shallbe based upon the ultimate use and zoning maps. A field


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review shall be utilized to verify the reasonableness of theprojections.

4.201.4 Flow Types. The type of contributor, residential,

commercial, or industrial, determines the level of flow thatmay be anticipated from each contributor. The flow ratesmay be determined from the ultimate land use accordingto the table presented in Appendix 4.1 of this manual.

Industrial flow may vary significantly with industry type,size, and method of wastewater discharge. The designengineer shall identify any industrial uses within theservice area and shall determine the magnitude of theindustries wastewater contributions to the sewer. Thedetermination shall be reviewed and approved by the CityEngineer.

4.201.5 Major Point Source Discharges. Major point sourcedischarges include flows from institutional, industrial, andcommercial establishments. Existing major point sourcedischarges within the tributary area shall be identified, andthe engineer shall confirm the exact discharge location ofthe major point source. Potential major discharges fromfuture point sources shall also be incorporated into the

design flows.

4.201.6 Inflow and Ground Water Infiltration. The sewer designcapacity shall include an allowance for extraneous flowswhich inevitably become a part of total flow. These flowsinclude ground water infiltration through defective pipes, joints, manholes, and cleanouts as well as inflow fromcross connections.

4.202 SEW ER FLOW CALCULATI ONS.

All new or replacement sanitary sewers shall be designedwith size and flow capacity as needed to accommodate theultimate conditions of the areas they serve. In certaincases in which the flow in an existing sewer main isincreased by proposed developments or improvements, theproject may be required to upgrade the existing system.


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4.202.1 Peaking Factor. The sewer design flows may be calculatedbased upon peak dry weather flows. Use of the followingequation shows the relationship between average dry

weather flows (ADWF) and peak dry weather flows (PDWF)expressed in cubic feet per second (CFS):

Q PDWF = 2.64 ( Q ADWF)0.905

4.202.2 Flow Contributions from Residential Populations. Flowsfrom residential populations shall be based upon theultimate density with the number of people per householddetermined as follows:

Residential Dwelling Unit = 3.5 people per unit

Accessory Unit = 70% of a dwelling unit =(0 .70) x (3.5 people per unit) = 2.45 people per unit

Daily per capita residential sewer flow contributions shallbe based upon 80 gallons per capita, per day (gpcd). TheCity of Encinitas bases sewer flow calculations on theconcept of Equivalent Dwelling Units (EDUs) whichconverts various kinds of sewer usages to an equivalent

multiple of residential dwelling unit usage.

1 EDU = (3.5 people/ residential dwelling unit) x 80gpcd

Wastewater discharge fees are assessed as apredetermined sum per EDU multiplied by the number ofEDUs of the proposed usage. Reference Municipal CodeCHAPTER 18.08 for information on EDUs and Appendix 4.4for information on the wastewater discharge fee.

4.202.3 Flow Contributions from Non-Residential Uses. Flowcontributions from non-residential uses shall bedetermined consistent with the average daily sewer flowprojections listed in Appendix 4.6.


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4.202.4 Sewer Flow Table. The table included as 4.4 of thismanual may be utilized for sewer flow calculations if, atthe discretion of the City Engineer, the complexity andscope of the sewer study do not necessitate computermodeling.


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4.300 SEWER SIZING AND MINIMUM REQUIREMENTS.

4.301 SEW ER DEPTH OF FLOW REQUI REMENTS.

Sewer pipes shall not be designed to flow at full capacity inorder to allow for the flowage of sewer gases. The gasesflow in the space between the wastewater surface and thetop of pipe. A sewer pipe full with wastewater inhibits thefree flow of air and sewer gases, creating a pressure whichpushes these gases through openings such as maintenanceholes. The sewer gases may be combustible or toxic andhave a strong undesirable odor. To avoid the odorproblems associated with the sewer gases, sanitary sewersshall allow for the transport of the air and gases by

designing the sewer to run less than full. Sewer mains andinterceptors less than 16 inches in diameter shall bedesigned to flow a maximum of half (50%) full, andinterceptor and trunk sewers of 16 inches or more indiameter shall be designed to flow a maximum of three-quarters (75%) full. At the discretion of the City Engineer,improvement to or upgrading of an existing sewer systemmay be required if the proposed development orimprovements result in the sewer main flowing more than50% full (75% for interceptor and trunk sewers 16 inchesin diameter and larger).

4.302 GENERAL SEW ER DESI GN CRI TERI A.The following general criteria apply to the design of sewersystems in the City.

A. Alignment. The preferred location of the sewer main ison the centerline. In cases in which a raised centermedian exists, the sewer shall be constructed outside ofthe median, unless otherwise approved by the City

Engineer. Where the sewer is located along the streetor alley centerline and the centerline is a curve, thesewer shall be constructed as a series of straightsegments connected by manholes. Alternately, thesewer may be constructed along the centerline with aminimum radius of 200 feet and in accordance with themanufacturers recommendations. Vertical curves andhorizontal curves less than 200 feet are discouraged


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and shall be approved in writing in advance by the CityEngineer.

B. Depth. The sewer main shall be buried a minimum of 5feet below grade to the top of the pipe and a maximum

of 20 feet below grade. Deeper sewer mains may beconstructed if allowed by the City Engineer in writing.An increase in depth will result in one or more of thefollowing requirements: a stronger pipe material,special beddings, concrete encasement and/oradditional easement width.

C. Structural Design Requirements. Structural design maybe required by the City Engineer if the clearancebetween the sewer and another utility is 18 inches orless. When a sewer pipe crosses another pipe or utilitytrench, the sewer pipe section shall be designed to spanthe utility trench and must be continuous for aminimum of 10 feet on either side of the trench or pipecenterline. A detail to be used in the case in whichpipes must cross is included in Appendix 4.3.

D. Location. Mainline sewers shall be located along streetor alley centerline whenever possible. Sewers mainsshall be located beneath the street pavement, notwithin the parkway. The sewer trench shall not be

allowed to extend underneath the sidewalk or curb andgutter areas.

E. Manhole Construction. Manholes shall be designed andinstalled as per the current San Diego RegionalStandard Drawing specification. The diameter of thebase ring of manholes shall be 60 inches. Theminimum diameter of the upper manhole rings shall be36. The inside of the sewer manholes shall be coatedwith epoxy in order to prevent the deterioration caused

by the sewer gases. In cases in which existingmanholes must be raised, such as for a street pavementoverlay, plastic riser rings shall not be allowed. Dropmanholes shall not be allowed for public sewers; analternative manhole design is included in Appendix 3.10of this manual.


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F. Manhole Locations. Manholes shall be provided atintersections of mains, at changes in slope, size, andhorizontal or vertical alignment, and at a maximum of350 feet on center. The use of horizontal and verticalcurves is discouraged; the utilization of both a

horizontal and a vertical curve or a reverse curvebetween manholes shall not be allowed. A manholewith a 5 stub or a cleanout, based on the CityEngineers discretion, shall be installed at the end of allsewers. Manholes shall be installed at the location ofintersection of a proposed main with an existing one.

G. Material. Sewers shall be constructed of PolyvinylChloride (PVC) with a minimum rating of SDR 35.Alternate materials may be utilized with prior writtenapproval from the City Engineer. All pipes shall bedesigned to withstand H-20 highway loading.

H. Private Sewer. Private sewer mains are not allowedunless approved in advance by the City Council. In thecase in which a private sewer is accepted, the sewershall be privately maintained and a private sewereasement shall be granted over the private sewer.

I. Radius. The minimum radius for a curved section of 8-inch pipe shall be 200 feet. Larger pipes may require a

larger radius. The manufacturers specificationsshowing that the sewer pipe joints can allow thedeflection necessary to achieve the radius shall beprovided to the City.

J. Separation From Water and Reclaimed Water Lines. Forspecial designs and restrictions for locations in which asewer must cross a water or reclaimed water main,please refer to Appendix 4.3.

K. Size. The sewer main shall be sized according to theprovisions of this chapter. The minimum sewer mainpipe size shall be an 8 inside diameter.

L. Slope. Sewer pipes shall be designed with a minimumslope of 1%, when possible. Where a 1% slope is notfeasible, the City Engineer may allow a minimum of0.4% slope.


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M. Velocity. The minimum design velocity shall be 2 feetper second. The roughness coefficient used incalculations shall be n=0.013. Because PVC sewermains suffer roughening of the inside pipe surface, the

roughness coefficient used for PVC sewers shall also ben=0.013.

4.303 SEW ER MAI N EXTENSI ONS AND CONNECTI ONS TO

THE SEW ER.

4.303.1 Requirement for Connection to Sanitary Sewer. Proposeddevelopment projects that trigger public improvementrequirements per Municipal Code Section 23.36 shall berequired to extend the sewer main and connect to thesanitary sewer unless the project qualifies for one or moreof the exceptions described below:

A. Single family residence (SFR) additions of less than 500SF of habitable and less than 750 SF of combinedhabitable and non-habitable additions are exempt fromsanitary sewer connection provided that the proposedaddition does not create a new residential orcommercial unit and the septic system has adequatecapacity to accommodate the additional flow.

B. SFR additions between 500 SF and 2000 SF of habitablearea or 750 SF and 2500 SF of combined habitable andnon habitable areas shall connect to sanitary sewer if asewer main is available adjacent or within the property,at the discretion of the City Engineer. If the sewermain is not extended to the property the City Engineermay require extension of a private sewer lateral to themain.

C. New SFRs on existing legal lots (not in connection witha subdivision), SFR additions greater than 2000 SF ofhabitable area or greater than 2500 SF of combinedhabitable and non-habitable area, and commercialadditions between 500 SF and 2000 SF which couldcreate additional sewer flow shall extend the sewermain if required and connect to the sanitary sewersystem. The main extension is normally equal to the


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property frontage contiguous to the sewer main or thelength necessary to bring the sanitary sewer to thenearest boundary of the subject property, whichever isgreater. The City Engineer may allow other acceptablesewer disposal/ improvements if the sewer main

extension required to service the property exceeds thelength of the property frontage contiguous to the sewermain.

D. In addition to the requirement to extend the sewermain along the property frontage and/ or the length ofthe property frontage and to connect to the sanitarysewer, multifamily residential, commercial, andsubdivision projects may be required to provide anoffsite (beyond the property) sewer main extension. Incases in which the proposed residential parcels are oneacre or greater in size, sewer is not available for a mainextension, and the proposed lots meet all CountyDepartment of Environmental Health requirements, analternate method of sewage disposal may be approvedby the City Engineer.

E. The City Engineer may require a project with a failingseptic system to connect to sanitary sewer regardless ofthe project scope. The County Department ofEnvironmental Health shall review and approve projects

proposing the expanded use of an existing septicsystem or the construction of a new septic system. Theapproval shall be obtained prior to issuance of a gradingor building permit, whichever is issued first. As perGeneral Plan Policy 1.12, development withinunsewered areas shall only be allowed after testingproves that septic systems would not create potentialpollution, and all development within unsewered areasshall be limited to parcels of at least one acre in size.

4.303.2 Requirement for Separate Sewer Laterals. Separate sewerlaterals are required for each lot, but a separate sewerlateral is not required for an approved accessory unit to asingle family dwelling located on the same property.

Projects proposing a condominium form of ownership foran existing or proposed development shall provide


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separate lateral connections for each condominium. Ashared lateral may be allowed by the City Engineer forcommercial or multi-family residential projects when ahomeowners association or other acceptable legal entity isestablished to ensure the maintenance of the sewer lateral

and assessment of costs into perpetuity.

4.303.3 Pumped Sewer Laterals. Private sewer pumps shall beallowed only when the City Engineer determines than noother alternatives exist or that an unnecessary hardshipwould be created by the requirement to provide a gravitysewer lateral.

In the case in which a sewer pump is proposed, theapplicant shall provide a design submittal to the City forreview and approval. The submittal shall be prepared by aregistered Civil Engineer and shall include the proposedpump specifications and details. The City shall review andapprove the application prior to issuance of a sewerdischarge permit and/ or prior to issuance of a grading orbuilding permit, if applicable.

The design for a pumped system shall include a privatemanhole located within the private property. The sewerlateral shall be pumped to the private manhole and

allowed to gravity flow from the manhole to the sewermain. The connection of a pressure lateral directly to thesewer main will not be allowed. A detail for the design ofthe required private manhole is included in Appendix 3.10of this manual.

4.303.4 Permits for Construction of a Sewer Lateral. A projectproposing to connect to the sanitary sewer system isrequired to obtain permits and pay required fees. The

permits required for a connection within the public right-of-way or a private street to an existing main include thewastewater discharge and sewer construction permitsissued by the Engineering Department and the plumbingpermit issued by the Building Department. A sewerconstruction permit is not required for a connection to asewer lateral which has been stubbed out from the main tothe property line, provided that no work within the public


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right-of-way or a public easement is necessary. Projectswith an existing connection to the sewer main proposing toaugment usage may be required to obtain wastewaterdischarge and plumbing permits; the Engineering andBuilding departments should be consulted to determine

which permits are required. The permits and feesassociated with the sewer connection or augmentation ofsewer usage are discussed below.

A wastewater discharge permit and the associated fees arerequired when a connection to the public sewer is beingadded, when a connection to a lateral stubbed out fromthe main to the property line is being made, and whenadditional sewer discharge is proposed. The sewer fees forCardiff and Encinitas Sanitary districts are assessed asindicated in Appendix 4.4. In the case of sewer lateralinstallation in a new subdivision or connections to a publicsewer main extension under construction, the issuance ofwastewater discharge permits may be deferred until priorto issuance of any building permits. Properties serviced byLeucadia Wastewater District shall obtain a permit fromLWD and shall pay the applicable fees assessed by thatdistrict.

A sewer construction permit shall be obtained for aconnection to a public or private sewer. Connection to the

sewer within the Leucadia Wastewater District requires apermit from LWD and a construction permit from the City ifthe work is proposed in the right-of-way, City easements,or City-owned properties.

In addition to the above fees, a sewer connection proposedwithin an area designated as a sewer reimbursementdistrict, reimbursement fees in accordance with Section4.600 below shall be paid.

4.303.5 Construction Requirements for Sewer Laterals. Sewerlaterals shall be a minimum of five feet deep at the projectproperty line in order to ensure adequate depth within thepublic right-of-way. Laterals shall comply with San DiegoRegional Standard Drawing SS-01 through SS-04 and shallbe a minimum of four inches in diameter for single familyhomes and units and six inches in diameter for other uses.


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Laterals shall not discharge directly into a manhole andshall have a minimum slope of 2%. Deviation from theserequirements shall be approved by the City Engineer inwriting. The private property owner is responsible for themaintenance and repair of the lateral serving his or her

property from its connection with the public sewer main toits termination on the private property. Permits arerequired for any work within public rights-of-way oreasements.

Sanitary sewer laterals are intended for the purpose ofproviding a connection of sewer service from one privateproperty to the sewer main. Sewer laterals generallyextend across public rights-of-way or public sewereasements. The extension of sewer laterals longitudinallyalong the street or public easement in order to avoid theconstruction of a sewer main extension shall not beallowed.

4.303.6 Grease/ Oil/ Sand Interceptors. Fats, greases, and waxescan adhere to sewer structures and appurtenances,obstructing flows, causing system back-ups and potentiallystorm water pollution. Flows containing such materialsshall be pre-treated prior to discharge into the publicsewer system by a process or device to remove the

materials from the flows. Grease and oil interceptors shallbe constructed of impervious materials capable ofwithstanding abrupt and extreme changes in temperatureand shall be watertight with easily removable covers thatare both watertight and gastight when secured in place.All grease, oil, and sand interceptors are required to bemaintained by the owner at owners expense. Failure toprovide or adequately maintain a grease, oil, and sandinterceptor when required by the City may result in acitation and an order to comply with the applicable

regulations in conformance with Section 18.04.120 of theMunicipal Code. All new restaurants and food preparationfacilities with the potential of releasing greases into thesewer shall provide grease traps to the satisfaction of theCity Engineer. Existing restaurant and food preparationfacilities without a grease trap and which propose anaddition in excess of 500 square feet shall also providegrease traps.


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4.303.7 Unauthorized Sewer Connection and Unauthorized SewerDischarge. No connections shall be made to the publicsewer system without prior submittal of an application for

sewer connection/ capacity, payment of applicable feesand reimbursement district costs, if any, and approval ofthe City Engineer authorizing the connection. Nomaterials, solid or liquid, may be disposed or dischargedinto the public sewer system without a permit issued bythe City.

No discharge of storm water, surface water, groundwater,unpolluted industrial process water, roof runoff, subsurfacedrainage, or any waters from a cooling system, swimmingpool, decorative fountain, or pond shall be allowed. Priorwritten permission from the City Engineer in conformancewith adopted regulations is required for any variationsfrom the prohibitions listed above.

Enforcement measures shall include any steps authorizedby law to collect any fees or charges due and possibledisconnection of the lateral from the public sewer system.Restrictions regarding the use of public sewers andenforcement measures are discussed in Sections18.04.080 through 18.04.110 of the Municipal Code.


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4.400 SEWER AND ACCESS EASEMENTS.

4.401 SEW ER EASEMENT REQUI RED.

A minimum 20 foot wide sewer easement shall be granted

to the City if the sewer is not proposed within the right-of-way. The sewer easement must be designed to allow truckaccess over the entire proposed sewer and shall becentered on the sewer main. In special circumstanceswhere a 20 foot wide easement is infeasible, an easementof 15 feet in width may be allowed, at the discretion of theCity Engineer.

No grading, trees, walls, fences, structures, or gates areallowed in the sewer easements. Landscape and irrigation

that impair truck accessibility will also not be allowedwithin the sewer easements. Enhanced paving may beallowed within the sewer easement with an encroachmentpermit provided that the paving is designed to withstandtruck loading.

In some cases, a sanitary sewer main may not be availableto service a certain area. The City Engineer may requireas a condition of sewer connection the dedication of apublic sewer easement to facilitate future expansion ofsewer infrastructure.

4.402 SEW ER ACCESS EASEMENT REQUI RED.

If the entire sewer easement is not accessible by trucksdue to natural topography, the City Engineer may requirean access road to provide maintenance truck access tomanholes and certain portions of the sewer system. Apublic sewer easement a minimum of 20 feet wide shall begranted over the entire access.

4.402.1 Requirements for Access Road. Minimally, sewereasements and access easements must be paved withgranular base material to withstand truck loading, allowall-weather access, and provide erosion control. Theminimum pavement section shall be six inches of class IIbase material topped with two inches of crushed rockfor erosion control purposes.


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Sewer easements and access easements shall be designedto include a 25 near-level area in front of access holes,and a hammerhead turnaround graded at no more than5% shall be provided for easements exceeding 250 feet in

length. Overhangs such as wires, tree branches, andbuilding eaves shall allow a minimum 15-foot clearancefrom the road. The minimum centerline radius shall be 36feet.

4.403 CONSI DERATI ONS FOR SEW ER EASEMENT LOCATI ON

AND WI DTH.

The minimum easement width is 20 feet. In circumstancesin which a 20 foot wide easement is infeasible, aneasement 15 feet wide may be allowed at the discretion ofthe City Engineer. Additional width is necessary if a seweris constructed at a depth greater than nine feet or if theground longitudinal or cross-slope exceeds 10%, or basedupon the special circumstances of the property or theproposed sewer.

Sewer easements should be as far as practical frombuildings. Footings and roof overhangs shall not be allowedwithin an easement. The vertical distance between thesewer and the footing must be such that excavating for

sewer construction or repair does not endanger thebuilding; the City may require additional easement width ifexisting or proposed buildings or structures are locatedrelatively close to the proposed sewer easement.Whenever possible, sewer easements parallel to lot linesshall not straddle the lot line but shall be located entirelyon one parcel.

4.403.1 Shared Sewer Easements. Typically, a sewer easement is

reserved for the exclusive purpose of a single utility pipe.Within a standard easement, a single sewer shall beconstructed at easement centerline to provide room foraccess and future maintenance.

If multiple pipes will occupy an easement, the City mayrequire additional easement width in order to allowadequate space for maintenance.


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Public sewer easements are for the exclusive use of publicsewers. The City Engineer shall approve in writingconstruction of any other utility or use with a public sewereasement. A conflicting use or placement of a utility which

impedes maintenance access shall not be allowed.

4.403.2 Sewer Within Private Street. When a public sewer isproposed within a private street, a sewer easement atleast 20 feet wide shall be granted over the sewer main inthe street. If the private street is not accessible from thepublic right-of-way without crossing over private property,an access easement to allow City access to maintain thesewer facilities may be required. Sewer access easementsare discussed in Section 4.402 above.

4.403.3 Granting of Sewer Easements. Sewer easements shall bededicated to the public on a map/ parcel map or dedicatedby a separate easement document. For information oneasements granted on a map, refer to Map Manual Section1.506.

When an easement is to be granted by a separatedocument, the City will prepare the easement document

language for processing by the developer. The developershall retain a qualified, licensed civil engineer or landsurveyor to prepare the legal description and plat of thesewer easement. Title reports or grant deeds showing thecurrent property ownership shall be provided to the City toassist in the preparation of the easement document.Lenders shall execute a City-approved subordinationagreement subordinating their interest in the property tothe public sewer easement. The proposed easement shallbe surveyed and the traverse tapes submitted to the City

for review and approval prior to recordation of theeasement. The easement document shall be recorded withthe County Recorder prior to issuance of any permit for thesewer construction.


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4.500 SEWER IMPROVEMENT PLANS AND PERMITS.

Proposed sewer main improvements must be permitted bya City improvement permit. The applicant shall processwith the City a sewer improvement plan. Standard notes

for sewer improvement plans are included as Appendix2.32 of this manual. When all City comments on the planshave been resolved through plancheck, the final drawingswill be approved. At that time, a letter will be issued tothe applicant detailing the final bond and fee requirementsfor issuing the permit. Following completion of thoserequirements, including payment of fees and posting ofsureties, the permit will be issued. Information on theimprovement permit application, plancheck, approval,bonding, and permitting process can be found in Chapter 2

of this manual.


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4.600 SEWER REIMBURSEMENT DISTRICTS

4.601 GENERAL I NFORMATI ON.

Pursuant to Health and Safety Code Section 4742.3 and

Encinitas Municipal Code Chapter 18.12, when publicsewers are installed, and the City Council determines thatthe sewer is necessary and can serve properties other thanthe property belonging to the person making theinstallation, the City Council may approve a sewerreimbursement district. The purpose of the sewerreimbursement district is to allow the developer to recoupa pro-rated portion of the sewer construction costs at suchtime as one or more of the properties identified in thereimbursement district connect to that sewer system. The

option of a sewer reimbursement district is available onlyfor public sewers within public sewer easements or streetrights-of-way. Upon the City Council approval of a sewerreimbursement district, the City will collect areimbursement fee from the property owners connecting tothe sewer. The amount of the total reimbursement fee isestablished based on the original installation costs plusinterest and is approved by the City Council.

4.602 ADMI NI STRATI ON OF REI MBURSEMENT AGREEMENTS.

The decision to establish a sewer reimbursement districtshall be agreed upon by both the City and the developer,and the developer shall agree to the stipulated terms ofthe reimbursement agreement. The establishment of asewer reimbursement district may be denied by the City ifthe developer fails to agree to the terms and policiesgoverning the establishment of a district.

The developer shall be responsible for all of the costsassociated with the construction of the sewer main

including, but not limited to, construction, easementacquisition, permitting, and administrative costs, and theowner shall pay a fee to the City as compensation forCitys costs to administer the agreement. A depositaccount shall be established with the City, and an initialdeposit in compliance with City requirements shall bemade in order to compensate the City for initial time and


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expenses until such time as the reimbursement districtagreement is finalized.

During construction of the sewer main, the developer shallretain invoices for all items to be included in the

reimbursement agreement and evidence of payment ofthose invoices. The copies of invoices and proof ofpayment shall be submitted to the City for considerationnot longer than 90 days following acceptance of the sewerby the City. Reimbursable costs shall ultimately beapproved by the City Engineer and may include paymentsmade by the developer for engineering, surveying, right-of-way or easement acquisition, permits, material testing,construction, inspection, and installation related to thesewer main.

The proposed sewer main shall be designed in accordancewith public standards and City requirements and to thesatisfaction of the City Engineer. Reimbursementpayments for the sewer reimbursement district shall becollected by the City for connections to the sewer madewithin the term of the agreement.

There are no assurances that the developer will recoup themaximum reimbursement amount or any portion thereof.The number of possible connections used to determine the

reimbursement fee is an estimate, and there is noguarantee that all or any of the connections will be made.Parcels will not be responsible for the reimbursement fee ifa connection is made after the expiration of thereimbursement district. Likewise, parcels will only beresponsible for the reimbursement fee if the parcelconnects a lateral directly to the sewer main as identifiedin the reimbursement district or if the parcel connects to afuture extension of that sewer main. If the City collectsany reimbursement fees, payment shall be sent to the

developer within ninety days of collection of the fee, untilthe developer has recouped the maximum reimbursementamount or until the agreement expires.

Information on sewer reimbursement districts can befound in Chapter 18.12 of the Municipal Code. Particularson the establishment of a district and an overview of theprocess are included in the City administrative manual,


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number G042, which is included in this manual asAppendix 4.5.

4.603 PROPERTI ES INCLUDED I N THE REI MBURSEMENT DI STRICT.

The developer shall engage the services of a registeredcivil engineer licensed to perform such work in order toprepare for the City information on which properties couldpotentially benefit from the construction of the sewermain, including the developers property or properties.Those properties shall be determined based upontopography, availability of necessary easements, and otherfactors which would allow or impede the connection of aprivate sewer lateral to the sewer from each property.Properties which would be required to obtain an easementover private property that has not been guaranteed by theterms of the agreement shall not be included in thedistrict. Properties which may connect only by use of apumped sewer lateral are not eligible for inclusion in thedistrict. The selection of parcels for inclusion into thereimbursement district is subject to review and approvalby the City Engineer.

A preliminary sewer improvement plan shall be submittedto the Engineering Department for review and commentprior to submittal of the sewer improvement plans. The

plan shall clearly delineate all properties that will beincluded in the proposed sewer reimbursement districtupon adoption of a Code change by the City Council, thepreliminary conceptual plan for the sewer reimbursementdistrict shall be approved by the City Council prior topreparation of the sewer improvement plans and issuanceof the improvement permit. Engineering approval of thepreliminary or final sewer plans shall not be construed asthe City Council approval of the sewer reimbursementdistrict, nor shall it be interpreted as any guarantee

whatsoever by City staff relative to the Council action onthe proposed sewer reimbursement district.

The number of parcels to be included shall be determinedbased upon the existing zoning at the time the sewer mainis constructed, and shall assume that vacant properties willbe developed to the mid-range density allowed by thezoning. If a single lot is assessed for more than a


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CITY OF ENCINITAS ENGINEERING DESIGN MANUAL - 2009residential or a commercial unit, the fees will be collectedat the time that each individual unit is developed.

In some situations, a parcel may have been included in anexisting sewer reimbursement district, but an extension of

the main constructed as a part of the reimbursementdistrict may be necessary to facilitate the desiredimprovement of that parcel. In such cases, the parcel isnot exempt from the terms of the reimbursementagreement as originally established and shall makepayment of the reimbursement fee prior to establishing aconnection to the sewer.

4.604 CALCULATI ON OF THE REI MBU RSEMENT FEE.

Once the parcels to be included in the reimbursementdistrict have been agreed upon by both the developer andthe City, the per-parcel reimbursement fee may becalculated. The fee shall be calculated by dividing the totalsum of costs determined by the City Engineer to be eligiblefor reimbursement by the total number of potentialconnections to service unconnected parcels. For example,if the reimbursable costs of the sewer main are$100,000.00 and there are ten potential connections, thereimbursement fee would be $10,000.00 per connection.

At the time that a new connection to the sewer main issought, a property identified in the district shall makepayment for the reimbursement fee together with anyother applicable sewer or permit fees prior to issuance of apermit for the connection. The total amount due prior toconnection shall be the original pro-rata share for theconnection, plus 6% annual simple interest accumulatedfrom the date the reimbursement district is approved bythe City Council to the date the City receives payment forthe reimbursement fee from each benefited party. The

total reimbursement to the developer shall not exceed themaximum reimbursement amount.

The developers property or properties will be included inthe determination of the total number of possibleconnections. The developers pro-rata share of the totalreimbursement amount shall be deducted from the totalreimbursable costs instead of collected at a later time.

Sewer Design01

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