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HomeMy WebLinkAboutUniform Design StandardsBRYAN/ COLLEGE STATION UNIFORM DESIGN GUIDELINES Domestic Water DO MESTIC WATER Table of Contents General Submittal Requirements ............................................... ............................... 1 SpecialDesigns ............................................................ ............................... 1 Connections................................................................. ............................... 2 Pipe Selection PipeMaterials ............................................................... ............................... 2 PipeSizing ................................................................... ............................... StandardPipe Sizes ..................................................... ............................... 3 LoopingRequirements ................................................. ............................... 3 Maximum Lengths ............................................... ............................... 4 Pressure /Flow Requirements ....................................... ............................... 4 Design Flow Calculation ............................................... ............................... 4 NormalFlow ................................................................. ............................... 4 FireFlows ..................................................................... ............................... 5 Fire Flow System Design Criteria ................................. ............................... 5 Pipe Alignment HorizontalLayout .......................................................... ............................... 6 VerticalLayout .............................................................. ............................... 6 FlushingDe sic; n ............................................................ ............................... 7 Deflections, L:, _;nds and Curves .................................... ............................... 7 Separation fron Wastewater Facilities ......................... ............................... 7 Valves Locationand Spacing ................................................... ............................... 8 TappingSleeves ........................................................... ............................... 8 Fire Hydrants Residential Fife Hydrants ............................................. ............................... 9 Non - Resident,:;) Fire Hydrants .............................. ....... ............................... Rightof Way Crossings ........................................................ ............................... 9 Encasements ......................................................................... ............................... 10 Easements ............................................................................. ............................... 11 Tables Table I — Fixture Units Per Unit or Group ..................... ............................... 11 Table II — Peak Water Demand Based on Fixture Units .............................. 12 Table III — A. _ : a Water Demands ........................................................... 12 ........................... Table IV - , . '. Vater Design Demands ............... .. ............................... Table V — Mir in Uni Radius for Water Pipe .................. ............................... 13 Effective 8/04/2000 DESIGN GUIDELINES Revised January 2004 DOMESTIC WATER GENERAL The purpose of this manual is to establish certain minimum criteria for the design of water distribution mains in the Cities' jurisdiction. It is intended to be used by the city staff and private consulting engineers for all new utility construction, replacements and modifications to the existing systems. Unusual circumstances or special designs requiring exception from the standards in this manual must be approved by the City Engineer. This manual is intended to be used in conjunction with all current American Water Works Association (AWWA) and "i xas Commission on Environmental Quality (TCEQ) requirements. Additionally, all design should be in accordance with the adopted version of the International Fire Code. In the case of a conflict between this manual and either or both of these other requirements, the most restrictive will govern. The criteria outlined in this manual are also intended to be 11:r_ �d in conjunction with the Cities' Unified Technical ;�;ifications. Fcr the purpose of this manual, water distribution mains are those mains of 18 inches in diameter or smaller. Larger diameter mains are considered to be transmission mains and are subject to additional design criteria and review. Submittal The design engineer shall submit the following information Requirements all water system designs: • Plan and profile sheets containing all information necessary to review, construct and inspect the improvements. This shall include a traffic control plan as applicable • Water Design Report showing that the design of the proposed improvements meets the requirements of this manual (such as fire flows, pressure, maximum run lengths, velocities, etc.) • Copy of information provided to TCEQ in compliance with TCEQ submittal requirements (TAC290) for City records purposes. If the project is exempted from TCEQ submittal, this submittal to the City is also exempted. Effective 8/04/2000 Page 1 DESIGN GUIDELINES Revised January 2004 DOMESTIC WATER Special Designs The City Engineer may, upon request, approve an alternative design or construction methodology that differed from the requirements in this manual if the City Engineer determines that: (1) the alternative design or construction methodology is equivalent to, or superior to, the methodology required in this manual, and (2) the alternative design or construction methodology is sufficient to ensure public health and safety. Connections A!I connections and service leads shall be installed to both sides of all roads and alleys at the time of main line ins�allation. Service connections to 16" or larger water mains shall not be allowed. PIPE SELECTION: Pi -)es shall be selected, sized and designed to provide a , -Z e, efficient and maintainable system for the conveyance of domestic water from existing supplies and systems to I / or existing users. Pipe Materials Ti, following pipe materials may be specified for water c'i_',ribution mains: Effective 8/04/2000 Ductile iron pipe (DIP), pressure class 350 for sizes 6 through 12 inches and pressure class 250 for 18 inches <<r. greater. Where excessive depths are encountered than 10 feet), the design engineer shall specify an z; thickness class to be approved by the City L.:✓ineer. P ;D,yvinyl chloride pipe (PVC) shall be SDR -21, ASTM L..- pressure class 200 for 3 inch; pressure class 200 Di�14 (meeting AWWA C -909 standards) for sizes 6 through 12 inches; and pressure class 235 DR18 (meeting VA C -905 standards) for pipe sizes 16 inches and c t _ter. PVC pipe will not be permitted for aerial c, casings. DI fittings shall be used with PVC pipe. Fittings ,.i be wrapped with eight -mil polywrap and sealed on the with an approved tape. 'K' copper tubing shall be used for all service lines 2 i --, es and smaller. ;:,ages in pipe material shall only occur at valves or with the exception of short replacements of water needed to meet TCEQ separation requirements. Page 2 DESIGN GUIDELINES DOMESTIC WATER Fir material information on pipe encasements refer to "Encasements" on Page 8. Pipe Sizing i'i i : s and pipe systems shall be designed to provide the . ce criteria listed below. Standard Pipe Sizes Tire standard pipe sizes for water distribution mains are 3, 6, 8, 10, 12, 16, 18, and 24 inches in diameter. As c:;�� issed in the "Maximum Lengths for Water Mains" Section, the smaller lines have restrictions for use. andard size service lines within the right of way shall be 1, 11 iz, or 2 inch Type `K' Copper. Looping Requirements ;rrr anent dead -end mains will not be allowed if looping L.,,_ are available. This may require extending the r lines beyond project limits. Dead -end mains will be allowed at ends of cul -de -sacs \.i,-:-, the only alternative is to loop lines down side lot lines i. residential subdivisions. It is preferred to use 3 inch c.;_:neter lines where maximum length as described in the follo,ving section is not exceeded. Maximum Lengths inch line may be allowed for permanent dead -end for Water Mains i Uns not exceeding 500 feet. A 6 inch main may be t .l.red up to a maximum of 1500 feet in length and must connect at each end to an 8 inch or larger main and shall I. no more than 2 fire hydrants or flushing points. �, .,,ere it is not possible to meet this requirement, a 6 -inch I;:ain may be extended to a maximum of 800 feet in length �., J hall terminate with a fire hydrant or blow -off assembly. . =Q rules shall dictate the number of services allowed on Pressure /Flow ` �.Ler distribution mains shall be sized to meet all of the Requirements : o requirements using a Hardy -Cross based analysis i ,od or methods encompassed in software packages as KY -Pipe, MikeNet, or Cybernet. Design Flow L- tl, normal and fire flows are needed for meeting the Calculation c sign criteria as established under Design Flow r_ �. ,flation and System Design Criteria. Effective 8/04/2000 Page 3 DESIGN GUIDELINES Revised January 2004 _ DOMESTIC WATER Normal Flow Or,e of the following three methods shall be used to c.:; mine the normal flows by which the water system is to Le designed. Hourly Flow = (Average Daily Flow)(4) • Method 1 — Fixture Count Determination For small demand uses, the "fixture unit" method of estimating peak water demand may be used in accordance with the current duly adopted City Plumbing Code. For larger multi- family, residential, institutional, commercial and industrial uses (over 500 fixture units), Tables I and II should be used. Table I shows a fixture unit value for various plumbing fixtures and groups of fixtures. Table II shows the probable peak rate of demand from systems consisting of various numbers of fixtures. Method 2 - Land Use Determination Table III contains the normal flow demands that are expected from a variety of uses. The population factor for residential land uses is 2.67 persons per unit, which is then applied to the actual number of units per acre, if known, or the maximum units per acre from the current land use plan if the property development is not yet finalized. The population factors for non - residential uses are 30 persons per acre for commercial, office and institutional uses and 15 persons per acre for Industrial uses. • Method 3 - Gross Area Determination In the absence of projected land uses, the demands contained in Table IV may be used. Fire Flows For the purposes of this manual, the following shall be used for fire flow determinations unless greater flows are required for hydrants near structures as per the adopted International Fire Code. Effective 8/04/2000 Page 4 DESIGN GUIDELINES Revised January 2004 DOMESTIC WATER 1500 gallons per minute for public hydrants in single family . Residential cr duplex residential areas (this flow may be split between two adjacent fire hydrants within 1000 feet of each other). 2500 gallons per minute for public hydrants in commercial • Commercial or multi- family areas (this flow may be split between two adjacent fire hydrants within 600 feet of each other). For onsite fire hydrants needed to obtain coverage of • Other /Hi -Rise commercial or other high density uses, the design engineer sh, consult the City Fire Marshal to obtain the specific fire f,; ., demands for each project via the International Fire C; ;Je. Fire Flow System - I ! ,- following criteria shall be met on all new water Design Criteria improvements. Under normal conditions, provide residual pressures in the area serviced by the system improvement to meet - i - CEQ requirements, and at all times a minimum static :Jessure of 35 pounds per square inch (psi). Under fire flow conditions, provide the required fire flow _.t the most hydraulically remote pairings of 2 adjacent e hydrants in the system improvement in addition to ,e peak hourly flow. A residual pressure of no less than 20 psi is required. • rovide maximum velocities of not more than 12 feet ,- er second (fps) during fire flow in both existing and cpcsed mains. This maximum velocity may be - on a case by case basis depending on the condition of the existing mains and if an engineering rL;;_:ation has been performed. • Conform to any area wide master plans, including over :sizing for future development. PIPE ALIGNMD Th- - 'e-ign of water distribution mains should provide for ec-. cmical access for maintenance and repair, reliability of and minimum disruption to surrounding facilities c'":..g repair operations. In all cases water facilities shall c�— , :.y ,. th TCEQ separation requirements. Horizontal Layout T he centerline of water distribution mains constructed in str rights -of -way shall be located as shown on the Tye_ :: al Utility Location Detail (Figures 9 and 10 in the Effective 8/04/2000 Page 5 DESIGN GUIDELINES Revised January 2004 DOMESTIC WATER c-'ti its section) and shall remain parallel to the right -of -way /lien possible. Where possible, avoid placing water line fittings and connections under paved and fenced areas. Vertical Layout WL..er distribution mains should be laid to as straight a as possible between cross street connections. alignment should avoid high or low points between c(_ _ , .�c ions. (See Flushing Design below) .. Lite: distribution mains 12 inches in diameter and sn. !!er shall have a minimum cover to finished surface of 4 Eighteen -inch diameter and larger mains shall have a mi;,;.num cover of 5 feet to finished surface. Flushing Design kf%".,tE;r distribution mains should have a means of a r,...ik,wm cleaning velocity of 5 fps. Additionally, fire 1 - : . .., _ is shall be placed close to low point as practical. F.:. , Fief valves and flushing appurtenances shall be placed a: locations including an air release valve at all 1 L_ ,s for lines 12" and larger and on smaller lines where t, ;. :)eal has an A of 10 or more. k: N, - end lines shall be designed to allow adequate f. �h:ng capability. A flushing assembly shall be provided f a., lines 8 inches in diameter and smaller, while lines c. . _ i .han 8" shall end at a fire hydrant. Main Size Blow -off 3" 1 6" 2" 8" 2" 12" 4" or Fire Hydrant 18" 4" or Fire Hydrant >_ 24" 6" Deflections, Bends and - ri;;ximum deflection of pipe is to be restricted as Curves s.. _ in Table V. Deflection for PVC pipe shall be made t; 3 pipe barrel and not at the joint, while ductile iron >!,all be deflected at the joints. Service connections sl i, liid be limited in curved sections of pipe and when r �3.sary shall require a tapped tee fitting. b ,r.ds and fittings producing a change in alignment Effective 8/04/2000 Page 6 DESIGN GUIDELINES Revised January 2004 DOMESTIC WATER c .`.cr han the deflection allowance of this manual shall L✓ c::" ained to the pipe and blocked to undisturbed soil. In <.udition, the pipe itself shall be restrained for a minimum cf ;-ints on either side of the alignment change. C_TvL� ±L.re of pipe shall be accomplished through multiple, c,. , c :d deflections as described above. The minimum ra'' us of curvature for water pipes is shown in Table V. Separation from 7mtion of public water and wastewater mains will be Wastewater Facilities c F: it with the current Rules and Regulations for Public ystems of the TCEQ. VALVES id, , ,._ .iniine valves 12" in diameter or less shall be gate `­..,­_-s ^/hereas valves in lines greater than 12 inch shall be L '_tc , valves. Location and r; ,t should be located: Spacing One (1) less than every leg of a cross connection. the end of temporary dead -end lines, 70 feet from end of the line for lines greater than 8" and 200 ;,A for lines equal to and less than 8 ". the end of a public line (unless there is a meter) On 2 legs of a tee connection. '.'airy 800 feet. �Viiere possible, place valves in green areas and id handicap ramps. f; .!I be required at the point of connection of a new 11 _ ,i an existing main unless the existing main 1 n i -I ne valve within 200 feet of the connection. VL_ .; call be placed at intervals not to exceed 800 feet rc ss of the distance between intersections. Wherever p- I - ;ey shall be located within 5 feet of a fire hydrant. Ti ILy Engineer may require additional valves to prevent un, _" ry disruptions of service. Fire hydrant lead va! . to be positively anchored to the main line. to be located so that no more than 4 valves are I a isolate a section of main. Effective 8/04/2000 Page 7 DESIGN GUIDELINES Revised January 2004 DOMESTIC WATER Tapping Sleeves Ta i-ri Sleeves and valves will be allowed unless size on siz - r ections are needed, and then Tee connections will b< ;red. A Tee connection may also be required where ri. ire valves are needed. FIRE HYDRANTS: Fir , are to be located at street intersections or as C . to an intersection as possible. Hydrants should not be L A vrithin the intersection curb return radius. I,�' ediate fire hydrants should be located near property l;.. nsions and no closer than 5 feet to any service line. Residential Fire !. , c. - �t tial areas fire hydrants should be placed within Hydrants ti -or" -way in the vicinity of the common lot lines. Pu fire hydrants shall be spaced 1000 feet apart in _.n ily districts at locations so that structures (or �.. ed lot) shall not be more than 500 feet from a fire I, t as measured along the right of way of a public fire hose is laid off the fire truck. !, I I :ntial areas with lots sizes of 5 acres or greater, fire I, r ; i: ,a y be spaced at 1,500 feet along the water main S�' structures shall not be more than 750 feet from a f r: drant as measured along the right of way of a public fire hose is laid off the fire truck. Non - Residential P ill hydrants in districts other than single family Fire Hydrants C. s ,all be installed as per the Cities Fire Codes. )proval by the City Engineer, the installation of >.;I public fire hydrants in such districts may be �. .nd required as a condition of the building F j or structures. !. , ;ce with TCEQ, fire hydrants shall not be placed c. . , ,. - in 9 feet horizontally and vertically from any �. main or appurtenance. All fire hydrants shall _..?d to a minimum 6 inch water main. is assary to place a fire hydrant in a proposed (- , cation, the sidewalk shall be widened or ! ti-) maintain the required sidewalk width. i. - a,)Ie for fire hydrants to be placed within 150 feet Iepartment connection on the structure. Page 8 DESIGN GUIDELINES Effective 8/04/2000 Revised January 2004 DOMESTIC WATER CROSSINGS: Effective 8/04/2000 Revised January 2004 is.ribution mains that cross state highways must c i to the Cities' Unified Technical Specifications and ti quirements of the Texas Department of r' ±ion (TxDOT). Mechanical bores are required for 1,1 ngs of existing streets. k . ' stribution mains that cross railroads must conform L, Cities' Unified Technical Specifications and the I ar - , nts of the railroad company whose right -of -way is sed. i distribution mains crossing creeks or drainage C, regulated by FEMA shall require encasement. L ,,de crossings are preferred; however aerial Ci may be considered. Thrust restraint shall be I.. at points of transition from buried to exposed pipe Z. I mges in alignment of exposed pipe. Air release .II be provided at the high point of all crossings. le crossings of creeks and drainage channels I I a minimum cover of 4 feet below the flowline at t of construction. All below grade crossings _ encasement shall be encased in steel c .t pipe and all ends shall be capped and sealed. ij shall be carried into the bank a distance that nsider changes in the creek channel. This C. ould usually be beyond the high bank such that if ured a 1:1 slope from the high bank away from ?i - �I, the casing would terminate at that location. Page 9 DESIGN GUIDELINES DOMESTIC WATER ENCASEMENTS: S, t �ider pipe shall be used for all encasement pipe. C . asement pipe material may be used per TCEQ r , nts and City Specifications. Carrier pipes sized r ic or less shall use an encasement pipe with a wall t no less than 3/8 -inch. For larger carrier pipes, a V. i ' ness of no less than 1/2 -inch shall be used. C ` encasement pipe may be required in special soil c -)l F :asement will be required for all water mains C' any street classified as major collector and greater i. , new streets regardless of method of installation. not apply to services. Special field conditions r. re an alternate method of installation, which must L - by the City Engineer. 'r ..sement pipe shall sized in accordance with the l" echnical Specifications and shall extend 2 feet L he back of both curbs on the street. Ends of c ent pipes shall be sealed to prevent the intrusion :tion of groundwater. pipes will be supported by casing spacers in with the specifications and details, and shall F: is restrained by an approved method that will allow t. �e ral of the carrier pipe from the encasement pipe in II rection by means of tension on the carrier pipe i. EASEMENTS: gins that are not proposed to be constructed and parallel to public rights -of -way shall be in c `s of not less than 15 feet in width. Water mains a "_;Tied deeper than 8 feet shall be in easements r, "an 20 feet. When unavoidable for both water ewater mains to be located within the same t: the width shall not be less than 30 feet unless i is buried deeper than 8 feet, in which case, c width shall be increased. Where water lines will , nt to building structures, easement width shall be dent must be located such that the centerline of t e is no closer than 5.5 feet to the closest edge anent. Page 10 DESIGN GUIDELINES Effective 8/04/2000 Revised January 2004 DOMESTIC WATER ins constructed adjacent to TOOT maintained r shall be located in the utility accommodation vided by TOOT. If there is no utility lation zone, or if the zone is occupied, then the shall be installed in a separate easement (min. ' jacent to the right -of -way. Effective 8/04/2000 Revised January 2004 Page 11 DESIGN GUIDELINES DOMESTIC WATER TABLE I FIXTI' — .E UNITS PER UNIT OR GROUP FIXTURE TYPE FIXTURE UNIT VALUE LOAD FACTOR One Bathroom Group - tank r 6 water closet, tub or shower, I .. Bathtub (with or without shov'cr) 2 Dishwasher (domestic) 2 Kitchen Sink 1 -with food grin 2 Lavatory 2 Shower Group, per he 3 Sinks, commercial - Surgeon's 3 - Flushing Rime (with ;ve) 8 - Service 3 -Pot (scullery, etc. 4 4 4 Urinals Washer, clothes Water Closets -Tank Operated 4 -Valve Operated 8 Effective 8/04/2000 Page 11 DESIGN GUIDELINES Revised January 2004 DOMESTIC WATER TABLE II PEAK WATE DEMAND BASED ON FIXTURE UNITS FIXTURE UNIT.' PEAK DEMAND (GPM) 500 125 1000 215 15 300 2000 330 ?500 380 3000 420 3�:v0 490 400 560 4500 630 50 700 6000 840 7000 980 3000 1120 �? 1260 1 "-1 0 1330 TABLE III L —AGE WATER DEMANDS Residential Commercial -Office - Retail -Hotel /Mot Institutional - Schools - Hospitals Indust Effective 8/0412000 Revised January 2004 Page 12 DESIGN GUIDELINES DOMESTIC WATER NOix TRIBUTARY AR A Le tha 25;. 250 -300 300 -500 500 -1500 150((, -3000 More than 3C: Effective 8/04/2000 Revised January 2004 TABLE IV oVATER DESIGN DEMANDS TABLE V ''ADIOS FOR WATER PIPE — CLASS 200 DESIGN DEMAND . .d. per acre 20 -ft. Joint 7000 220 ft 6500 400 ft 5500 600 ft 5000 4500 4000 TABLE V ''ADIOS FOR WATER PIPE — CLASS 200 DUCTILE IRON 20 -ft. Joint (18-ft. 220 ft 400 ft 400 ft 400 ft 600 ft 400 ft Page 13 DESIGN GUIDELINES BR`. .P: ALLEGE STATION UNIFC RC `.SIGN GUIDELINES . ►nary Sewer SANITARY SEWER able of Contents General 1 SubmittalRequirem _ ............................................... ............................... 2 SpecialDesigns......... ............................................... ............................... 2 Connections............. ............................................... ............................... 2 Pipe Selection Pipe Materials........... Pipe Sizing ............... Standard Pipe Size: Minimum Pipe Sizes. Flow Requirei»ents.. Flow CalcuiZ.;L,on ...... System Design Crit_ ............................................ ............................... 2 ............................................. ............................... 3 ............................................ ............................... 3 ............................................ ............................... 3 .............................................. ............................... 3 ................................................. ............................... 3 ............................................... ............................... 5 Pipe Alignment HorizontalL , out...... _ ............................................ ............................... 6 VerticalLayuL;t......... .......................................... ............................... 6 Separatior, From 1 ities ................................. ............................... 6 Manholes............................ ............................................ ............................... 7 RightOf Way Cr,c ::, igs . ............................................... ............................... 7 Encasements..................... .......................................... ............................... 8 Easements......................... ........................................... ............................... 9 Tables Table I — Fi;aLre U.. it Or Group ..................... ............................... 10 Table II — Pc �- lk a i =lows Based On Fixture Units ........................ 11 Table III — Av -:rage 'ater Generations ............... ............................... 11 Table IV - -- ::, ,sign Flows ....................... ............................... 12 Effective 8/04/2000 DESIGN GUIDELINES Revised January 2004 Submittal Requirements SANITARY SEWER engineer shall submit the following information 'ewater system designs: Jan and profile sheets containing all information accessary to review, construct and inspect the , inprovements. This shall include a traffic control !an as applicable _;igineer may, upon request, approve an _ _<';gn or construction methodology that differed f . uirernents in this manual if the City Engineer G that: (1) the alternative design or construction rr is equivalent to, or superior to, the n squired in this manual, and (2) the alternative d :, ,struction methodology is sufficient to ensure f- Id safety. opy of information provided to TCEQ in c;ripliance with TCEQ submittal requirements ;;C317) for City records purposes. If the project exempted from TCEQ submittal, this submittal the City is also exempted. Special Designs Connections PIPE SELECTION, Pipe Materials _.�,iewater Design Report showing that the sign of the proposed improvements meet the - �w requirements of this manual. , 3sign shall follow acceptable engineering - e reviewed by City staff. i .al connections and service leads shall be il both sides of all roads and alleys at the time of n aliation. .lions shall be tied into the main line. ba designed to provide a safe, efficient and -- for the collection of wastewater from its of generation to the existing collection and i slams. i;ig pipe materials may be specified for V ; � ilection, and force mains as well as service li City's rights -of -ways. Effective 8/04/2000 Revised January 2004 'age 2 DESIGN GUIDELINES SANITARY SEWER L p ire (DIP), pressure class 350 for sizes 6 t' :;`yes and pressure class 250 for 18 inches and c )rcu mains shall be DIP, pressure class 350 or 1 pressure class 160 and shall not be greater in riches. f icri Je pipe (PVC) and all fittings shall be SDR26- i ';4 in sizes 6 through 15 inches and SDR26- T f 1 for larger sizes. PVC pipe will not be r r aerial crossings. :_. ormation on pipe encasements refer to the s section of this document. ;;,e material shall only occur at manholes with t if short replacements of sewer lines needed t - 6eparation requirements. Pipe Sizing systems shall be designed to provide the listed below. Standard Pipe Sizes I'ipe sizes for wastewater collection mains are nd 18 inches in diameter. Standard service be more than 150 feet in length and shall eanout at the property line. Minimum Pipe Sizes n a",ewater pipe sizes shall be as follows: :,:on Mains — 6 inches ntial Service Leads — 4 inches �rcial Service Leads — 6 inches Flow Requirements ection mains shall be sized to meet all of the :?ments using an analysis method based on Flow Calculation following three methods shall be used to _.eak hourly flows by which a new wastewater fringes of the existing system is to be c new systems being developed within the consult the City of Bryan Wastewater ;r design criteria). In each method, the _.ins apply: Effective 8/04/2000 'age 3 DESIGN GUIDELINES Revised January 2004 SANITARY SEWER F'. , w = (Average Daily Flow)(4) 1 - f=ixture Count Determination ti- family residential, institutional, commercial ustrial uses, the "fixture unit" method of ,!,g peak wastewater generation may be used dance with the current duly adopted City Code. Table I shows a fixture unit value for )lumbing fixtures and groups of fixtures. shows the probable peak rate of flow n from systems consisting of various of fixture units. Land Use Determination Effective 8/04/2000 Revised January 2004 contains the average daily flow per capita to -fled from a variety of uses. ,lation factor for residential land uses is 2.67 per unit, which is then applied to the actual ,;f units per acre if known, or the maximum I ,r acre from the current land use plan if the development is not yet finalized. .:lation factors for non - residential uses are 30 per acre for commercial, office and ,al uses and 15 persons per acre for . uses. Toss Area Determination d the boundaries of the current City of Bryan ter Master Plan and /or in the absence of land uses, the average daily flow per acre 1 in Table IV may be used. 'age 4 DESIGN GUIDELINES SANITARY SEWER t - idistorical Data is information regarding average daily flows 'irticular type of development that is more than the data from the other methods, the iformation may be used. Please discuss this City prior to using so as to ensure the )n is acceptable. System Design Criteria \ ins and collection lines shall be designed to c _ daily load estimated from the tributary areas - �veloped to the current land use plan. C of peak loadings shall be based on an density and character of the land uses in the t. :Id the probable wastewater generation from t .MUM / MAXIMUM PIPE SLOPES khan 36 inches in diameter, the slope may be Manning's formula to maintain a minimum than 2.5 feet per second when flowing full i velocity less than 8 feet per second when using a Manning's °n" of 0.013. Effective 8/04/2000 Revised January 2004 'age 5 DESIGN GUIDELINES SLOPE ( %) MINIMUM MAXIMUM 0.50 12.30 0.40 5.30 0.30 3.90 0.25 3.10 0.20 1.80 0.20 1.20 0.20 0.90 0.20 0.70 khan 36 inches in diameter, the slope may be Manning's formula to maintain a minimum than 2.5 feet per second when flowing full i velocity less than 8 feet per second when using a Manning's °n" of 0.013. Effective 8/04/2000 Revised January 2004 'age 5 DESIGN GUIDELINES SANITARY SEWER should be consistent between manholes and �ductions in velocity. PIPE f the wastewater collection mains should ALIGNMENT: nical access for maintenance and repair, r ' ation and minimum disruption to surrounding repair operations. In all cases wastewater S s - mply with TCEQ requirements. Horizontal Layout Tins and collection lines should be laid straight soles and at a uniform distance from the right of wastewater mains and collection lines street rights -of -way shall be located as shown utility Location Detail (Figures 9 and 10 in the sE , on the opposite side of the street from the is Vertical Layout &Jmum cover for sanitary sewer pipe shall be as measured from the outside top of pipe fished ground or pavement surface elevation. ;essary to reduce the cover, the design shall iron pipe and may include cement stabilized y covers less than 3.5'. Any shallow depth ! be discussed with the City Engineer. a .ins and laterals should be laid on a straight manholes while avoiding excessive depths. .L i)e shown on construction plans at 100 -foot L all manholes and match marks. Elevations ;fated to the nearest 0.01 foot. ,ins and collection lines must be constructed .. hich will insure gravity flow in service adjacent properties. In general, this is - )li y setting a 2% grade from the centerline of nain to a point one (1) foot below floor building line of the structure being served. i must have a minimum cover of 2 feet at its )e 1t including roadside drainage ditches where o` ublic water and wastewater mains will be Separation From , k e current Rules and Regulations for Public Water Facilities ji the TCEQ. Effective 8/04/2000 Je 6 DESIGN GUIDELINES Revised January 2004 SANITARY SEWER GENERAL: 1" � se of this manual is to establish certain minimum t design of wastewater collection mains in the C - isdiction. It is intended to be used by the city staff ate consulting engineers for all new utility C gin, replacements and modifications to the existing S Unusual circumstances or special designs rc exception from the standards in this manual must ti A by the City Engineer. ,al is intended to be used in conjunction with all C - ,erican Water Works Association (AWWA) and oinmission on Environmental Quality (TCEQ) r_ ts. In the case of a conflict between this manual or both of these other requirements, the most r :ill govern. - i outlined in this manual are also intended to be .jnjunction with the Cities' Unified Technical Dns. ose of this manual, wastewater collection mains ,ains of 18 inches in diameter or smaller. Larger C. wins are considered to be interceptor or t n mains and are subject to additional design review. F stewater collection systems that accept flows ,g upstream sewers shall be designed to ate all flows generated by the upstream service e existing upstream sewers may experience flows greater than the peaks utilized in the %v sewers. The peak flow rates (particularly the i. low rates) for each existing subsystem is highly Consult with the City Engineering Services to confirm the proper peak flow rates to be used fc :sting upstream wastewater collection system. T s- wastewater collection system design shall ,ew of all existing downstream sewers receiving e proposed sewers to verify that flows generated rc;josed wastewater collection system do not :act the performance of the downstream Page 1 DESIGN GUIDELINES Effective 8/04/2000 Revised January 2004 SANITARY SEWER wi!' be required at changes in horizontal MANHOLES: chi ,ges in grade, changes in pipe size or and 'tf ,her wastewater mains or collection lines. be required at the junctions where service t g new sewer lines into existing manholes, ride a point of connection. _Im distance between manholes shall be as per 'ie of TCEQ. in the size of a wastewater main or curs without a change in grade, the inside :) elevations will be matched in the manhole. -aces between pipes at a manhole may Whole (see TCEQ for more information). of a main or collection line, the line shall be w i a manhole or clean out as per TCEQ an extension is anticipated, a plugged stub- ,le joint with a clean -out is required. be constructed of fiberglass or concrete. ale may be cast in place or precast. oles may only be used in non - structural ,c. `call be as follows: ! ameter Main Size < 18 in. >_ 18 in. <30 in. >_36 in. ction mains that cross state highways must RIGHT -OF -WAY th Cities' Unified Technical Specifications and CROSSINGS: of the Texas Department of Transportation ection mains that cross railroads must "ties' Unified Technical Specifications and of the railroad company whose right -of -way Effective 8/04/2000 Revised January 2004 e 7 DESIGN GUIDELINES SANITARY SEWER ollection mains crossing creeks or drainage must support the elevated sections of such ossings of creeks and drainage channels imum cover of 3.5 feet below the flowline at ruction or shall be constructed of ductile iron e ption is to adequately protect the pipe from y concrete encasement or other approved , e specific information in Specification 400. ,ings of existing streets unless otherwise City Engineer. )e shall be used for all encasement pipe. ENCASEMENTS: !,t pipe material may be used per TCEQ J City Specifications. Carrier pipes sized 30 all use an encasement pipe with a wall than 3/8 -inch. For larger carrier pipes, a no less than 1/2 -inch shall be used. i�ment pipe may be required in special soil to look into type of encasement pipe) t will be required for all wastewater :;rossing any existing street and on new is major collector or greater . This does ices. Special field conditions may require od of installation, which must be approved per. diameter shall be twice the outside r er pipes sized from 6 inches up to 12 �s of carrier pipe material. Ductile iron _,d 12 inches and greater shall have an size 12 inches larger than the outside ,arrier pipe. PVC carrier pipes sized 12 �r shall have an encasement pipe size 10 the outside diameter of the carrier pipe. s shall extend 2 feet beyond the back of street. Ends of encasement pipes shall be ent the intrusion and collection of Effective 8/04/2000 Revised January 2004 e 8 DESIGN GUIDELINES SANITARY SEWER will be supported by Cascade carriers (or that will allow the removal of the carrier Incasement pipe in a single direction by i i on the carrier pipe only. EASEMENTS: ; constructed outside of public rights -of -way ents of not less than 15 feet in width unless is deeper than 4 feet, in which case, shall be increased to 20 feet. If both water mains are located within the same r,dth shall be not less than 20 feet unless iried deeper than 14 feet, in which case, hall be increased to 30 feet. ust be located such that the centerline of t ne is no closer than 5.5 feet to the closest nent. ction mains constructed adjacent to TOOT i vays shall be located in a utility easement. e allowed within a utility accommodation TOOT on a case by case basis. Effective 8/04/2000 Revised January 2004 ge 9 DESIGN GUIDELINES 3LE FIX �R UNIT OR GROUP FIXTURE One Bathroom Group — to water closet, tub or shows Bathtub (w o r without sl Dishwater (do m e stic) Kitchen Sink With food grinder Lavatory Showe G p er head Sinks, commercial - Surgeon's - Flushing Rim (witl - Service -Pot (scullery, etc.) U rin a ls Washer, clot Water Closets -Tank Operated -Vale_ Operated FIXTURE UNIT VALUE LOAD FACTOR 6 2 2 1 2 2 3 3 8 3 4 4 4 4 8 PEAK WASTE FIXTURE UC. 500 1000 1500 2000 25 v V 00 4000 4500 500 6C 00 1 � 0 Residentia Commercial - Office - Retail -Hotel /Motel Institutional Industri 3LE II 1S BASED ON FIXTURE UNITS PEAK DEMAND (GPM) 125 215 300 330 380 420 490 " I f •:f 1120 12 1330 3LE III :TER GENERATIONS AVERAGE FLOW GPD /CAP 100 50 25 150 35 200 50 'LE IV Y DESIGN FLOWS TRIBUTr,RY f DESIGN DEMAND (A�, L s (g.p.d. per acre) Less than 2- 7000 250 - 300 6500 300 - 50C 6000 50C - -j 5500 OC 5000 20r-Y .. _ . 4 500 gore 4000 V 9 BRY.Al - nAw u -EGE STATION :"]'N GUIDELINES -:) s a ry GLOSSARY ADA - in Disabilities Act Alley - )r public right -of -way which provides a ,ry means of vehicular access to abutting and which is used primarily for vehicular the rear or side of properties which otherwise a public street. City micipality of the City of Bryan. City Engineer of administrative employee of Engineering or his /her duly authorized representative(s). City Manag --: ` administrative employee of the City Council, r duly authorized representative(s). Collection Line , water line which receives only the flow from property. Collection M.-.111 :water line which receives the flow from property and from one or more collection mains. Collector S.. act I.Vhich primarily serves vehicular traffic from eets and minor collectors to arterials. A r may also provide very limited access to ;properties if approved by the City. Conduit - �d device for conveying flowing water. Critical Fea:re ral and readily identifiable part of an cture system, without which the effect(s) :.y the entire system would be compromised. Design Engineer :nsed Professional Engineer. Developer /Cjilder partnership, or corporation engaged in the lent of land and /or building of structures and r,led by exemption sections of this manual. Developmc; -made change to improved or unimproved including but not limited to buildings or uctures, mining, dredging, filling, grading, excavation, drilling operations, grading, or Effective 8/0 DESIGN GUIDELINES Revised January 2003 GLOSSARY Environmental Protectic ;i States Environmental Protection Agency, Agency (E" ., _,Al office thereof, any federal department, )r commission that may succeed to the of the EPA, any duly authorized official of - ach successor agency. Extra- Territcral Jurisdic :orporated area, not a part of any other city, (E.T.J.) ;ontiguous to the corporate limits of the City the outer boundaries of which are from the extremities of the corporate limits outward for such distances as may be A the Texas Municipal Annexation Act, in a, within the terms of the act, the City may violation of it's subdivision control chapter. Hydraulic Gradient oresenting the pressure head available at point within the drainage system. Interceptor ,ter line which receives flow from collection ,'or mains but not from any abutting Licensed Professional who has been duly licensed by the Texas Engineer (PE) Professional Engineers to engage in the )f engineering in the State of Texas. Local Juris ..:ot;on governing body in which the construction ;e (known also as `the City'). Local Strc�_ _ iich primarily serves vehicular traffic to .sidential properties. A local may also ,,sited access to commercial properties if b the City. Major Arterial Street which carries high volumes of vehicular the general range of 20,000 VP to 60,000 % is intended to move traffic in, out or City. Minor Ac ...i Strect .. h1ch carries high volumes of vehicular general range of 5,000 VP to 30,000 .ich is intended to move traffic around the Effective 8104L DESIGN GUIDELINES Revised January 2 ; GLOSSARY Minor Collector Street .vhich primarily serves vehicular traffic from ;ets to collectors or arterials. A minor may also provide limited access to abutting if approved by the City. Additionally, the '�ntified as collectors on the Thoroughfare be designed as minor collectors only if '�y the City. Operator or persons who, either individually or aher, meet the following two criteria: y have operational control over the site .cifications (including the ability to make c:ifications in specifications); and �y have the day -to -day operational control ti,ose activities at the site necessary to re compliance with plan requirements Hermit conditions. Other Munic .:I Ordinar. - �s such as, but not limited to, zoning, i, and building. Owner ,n �::iho owns a facility or part of a facility. Parkway between the back of curb and right -of -way �.rea is usually maintained by the property )rivate association. Pavement th In the portion of the surface of the street for traffic: where curbs are used, it is between the back of curbs. Qualified P rsonnel Nhj possess the appropriate competence, A ability (as demonstrated by sufficient training, experience, and /or, when any required certification or licensing) to pecific activity in a timely and complete insistent with the applicable regulatory As and generally- accepted industry or such activity. Effective 8/04/2 ,33 DESIGN GUIDELINES Revised January 2C -1 3 Fj,RYAV _GE STATION N GUIDELINES sary GLOSSARY ADA i Disabilities Act Alley r public right -of -way which provides a , - y means of vehicular access to abutting and which is used primarily for vehicular 'he rear or side of properties which otherwise i public street. City icipality of the City of Bryan. City Engineer ;f administrative employee of Engineering . or his /her duly authorized representative(s). City Mana �dministrative employee of the City Council, Duly authorized representative(s). Collection U,1w , ter line which receives only the flow from property. Collection l A ,mater line which receives the flow from property and from one or more collection gins. Collector : -.. ; et i, )ich primarily serves vehicular traffic from ,::ts and minor collectors to arterials. A may also provide very limited access to Dperties if approved by the City. Conduit A device for conveying flowing water. Critical Fea'Lre al and readily identifiable part of an `ure system, without which the effect(s) the entire system would be compromised. Design En i, er �d Professional Engineer. Developer; 7 'Ider partnership, or corporation engaged in the it of land and /or building of structures and , d by exemption sections of this manual. Developw - .ade change to improved or unimproved , including but not limited to buildings or _ - tures, mining, dredging, filling, grading, �Ycavation, drilling operations, grading, or Effective 8 /C. ; . — DESIGN GUIDELINES Revised Januu; �� GLOSSARY Environme,i;al Protectic States Environmental Protection Agency, Agency ( office thereof, any federal department, commission that may succeed to the the EPA, any duly authorized official of successor agency. Extra -Te Jurisdic:i , area, not a part of any other city, (E.T.J.) tiguous to the corporate limits of the City the outer boundaries of which are - om the extremities of the corporate limits outward for such distances as may be the Texas Municipal Annexation Act, in within the terms of the act, the City may olation of it's subdivision control chapter. Hydraulic Grz dient ,senting the pressure head available at Ant within the drainage system. Intercept r �r line which receives flow from collection mains but not from any abutting Licensed Professional .o has been duly licensed by the Texas Engineer (PE) ofessional Engineers to engage in the .ngineering in the State of Texas. Local )verning body in which the construction ;known also as 'the City'). Local Str :ch primarily serves vehicular traffic to ;idential properties. A local may also '. - access to commercial properties if the City. Major Arter t.: 'scot ',ch carries high volumes of vehicular general range of 20,000 VP to 60,000 ch is intended to move traffic in, out or ity. Minor At, Street ,;ch carries high volumes of vehicular general range of 5,000 VP to 30,000 `h is intended to move traffic around the Effective 810412, Revised January DESIGN GUIDELINES GLOSSARY Minor Col' :c r Street ch primarily serves vehicular traffic from to collectors or arterials. A minor y also provide limited access to abutting approved by the City. Additionally, the `ified as collectors on the Thoroughfare e designed as minor collectors only if the City. Operator or persons who, either individually or or, meet the following two criteria: ;ave operational control over the site cations (including the ability to make cations in specifications); and nave the day -to -day operational control _ se activities at the site necessary to - e compliance with plan requirements J )ermit conditions. Other Mur,ic:, ,:1 Ordinar, such as, but not limited to, zoning, ind building. Owner .ho owns a facility or part of a facility. Parkway meen the back of curb and right -of -way ea is usually maintained by the property irivate association. Pavemen' ,.:_�� the portion of the surface of the street traffic: where curbs are used, it is tween the back of curbs. Qualified ' ' e, .;cnnel possess the appropriate competence, ability (as demonstrated by sufficient i, :raining, experience, and /or, when ny required certification or licensing) to �_ecific activity in a timely and complete sistent with the applicable regulatory and generally- accepted industry such activity. Effective 8/G:I� 0 DESIGN GUIDELINES Revised Janua11" .. GLOSSARY Recreat; a: °1 YliL cle which is (i) built on a single chassis; ire feet or less when measured at the ontal projections; (iii) designed to be A : or permanently towable by a light duty I designed primarily not for use as a swelling but as temporary living quarters - ) ,- ,al, camping, travel, or seasonal use. Registers L ,n6scape has been duly licensed and registered Architec' �) _A) landscape architecture by the Texas iitectural Examiners. Rural Col' c jr Street : ETJ of the City which primarily serves fic from locals to arterials. A rural provide limited access to abutting F roperties if approved at the time of ie City and County. Construction and of the rural collectors are generally sdiction of the County. Rural Loc, l " reet 3 ETJ of the City which primarily serves is to abutting residential properties. A iay also provide limited access to roperties if approved at the time of City and County. Construction and oc r,f the rural locals are generally under :n of the County. Sanitary -r (or Sewc , i of pipes, conduits, and other which carry industrial and domestic their sources, whether treated or ',ie sewage treatment plant serving the .'hich stormwater, surface water, and re not intentionally admitted). Service L ac: - ; ne extending from a collection line or ;vate property or easement line making 'o the private service, including the lout(s). Site :ter area where any facility or activity is :Jed or conducted, including adjacent - nnection with the facility or activity. TAS Aity Standards Effective 8 /C ;, DESIGN GUIDELINES Revised January '. jC', GLOSSARY Use for which a building or other structure land may be designed, arranged, ntained, or occupied; or any activity, ,usiness, or operation carried on, or be carried on, in a building or other n a tract of land. Use Pcro,; . required before any use may be Variance to a person from the requirements of hen specific enforcement would result .ry hardship. A variance, therefore, ruction or development in a manner libited by this manual. Violat'mil a structure or other development to be t with this manual. Effective 8/04/2 . Revised Januar. 103 DESIGN GUIDELINES Ii�,5`03 Enp_ineerin2 Related 1. The City should adopt written Design Standards that are followed consistently by City staff. 2. Staff should receive ongoing training in City Standard Specifications and applicable regulations to ensure that requirements are interpreted consistently among city departments. 3. Engineering should establish a procedure or protocol for notifying departments involved in development review when a field change is made. 4. The City should adopt a standard policy that requires developers to submit "as- built" plans to the City before a Letter of Completion is issued. 5. The City should develop a procedure to ensure that warranty items that are identified as requiring repair are corrected. 6. The City should modify current procedures to require a Letter of Completion before work orders are executed. 7. The City should improve its enforcement of requirements that are based upon City ordinances or other established laws or regulations. Development Services Related 1. Development Services should review their 5 -day turnaround policy to determine if that is sufficient time to thoroughly review all construction plans. 2. City engineers reviewing development plans should conduct a more thorough review to minimize field changes, even if it extends past the 5 -day turnaround time. 3. Development Services, Public Works, and College Station Utilities should create a checklist that lists requirements developers must meet to obtain a temporary Certificate of Occupancy. 4. Regular meetings between city departments involved in the development review process should be established and implemented. 5. Staff members should be involved in the fact - finding phase of developer complaint resolution. 6. Written guidelines with approximate timeframes for completion of the development review process should be provided at pre - application conferences, or upon the developer's initial contact with Economic Development. 7. Additional guidelines should be established for redevelopment projects, specifically infrastructure guidelines. College Station Utilities Related Economic Development Related 1. Development Services should be included in the economic development process as soon as a site is identified. City Management Related 1. City management should organize all engineering and infrastructure inspections as one department under a director that reports to the City Manager /Assistant City Manager. 2. City management should identify all gaps in inspections, assign appropriately, and provide necessary resources to perform inspections. 3. City engineers should be organized in one department reporting to one person. This department should be a department separate from Public Works and Development Services, thus fostering the expectation that the engineering function will respond consistently throughout the development review process. 4. The City Manager should designate and notify applicable departments of those development projects that need to be expedited. 5. The new Design Standards should delegate authority to the City Manager or his delegee to make minor modifications to the City's Design Standards. (11) There is a lack of creative /discussion sessions among the departments involved in the review process. (12) Communications and concerns among the departments involved in the review process are not always shared and ultimately resolved. (13) Conflicting interpretations of City of College Station Standard Specifications or other regulations exist among City departments involved in the development process. Consistency in Decision-MakinE (14) Staff perceives that development complaints to City management are sometimes resolved without staff input. (15) On occasion staff issues a Certificate of Occupancy before the City accepts the infrastructure. (16) There is a lack of City Design Standards. (17) Staff sometimes makes requirements of developers that are not specifically written in the City's ordinances. (18) Existing guidelines for redevelopment are minimal. Public Perception (19) There are no current written development process guidelines for developers or Economic Development clients. Recommendations This report contains a variety of recommendations to address the identified shortcomings including: City management should organize all engineering and infrastructure inspections as one department under a director that reports to the City Manager /Assistant City Manager. n Development Services should review their 5 -day turnaround policy to determine if that is sufficient time to thoroughly review all construction plans. (3) Development Services engineers reviewing development plans should conduct a more thorough review to minimize field changes, even if it extends past the 5 -day turnaround time. I (4) Staff should receive ongoing training in City Standard Specifications and applicable regulations to ensure that requirements are interpreted consistently among City departments. (5) Public Works engineering should establish a procedure or protocol for notifying departments involved in development review when a field change is made. (6) City management should identify all gaps in inspections, assign appropriately, and provide —� necessary resources to perform inspections. (7) The City should adopt a standard policy that requires developers to submit "as- built" plans to the City before a Letter of Completion is issued. 8) The City should develop a procedure to ensure that warranty items that are identified as requiring repair are corrected. (9) Development Services, Public Works, and College Station Utilities should create a checklist that lists requirements developers must meet to obtain a temporary Certificate of Occupancy. 2 (10) The City should modify current procedures to require a Letter of Completion before work orders are executed. City engineers should be organized in one department reporting to one person. This department should be a department separate from Public Works and Development Services, thus fostering the expectation that the engineering function will respond consistently throughout the development review process. (12) The City Manager should designate and notify applicable departments of those development projects that need to be expedited. (13) Development Services should be included in the economic development process as soon as a site is identified. �14) Regular meetings between City departments involved in the development review process should be established and implemented. (15) Staff members should be involved in the fact - finding phase of developer complaint resolution. (16) Written guidelines with approximate timeframes for completion of the development review process should be provided at pre- application conferences or upon the developer's initial contact with Economic Development. - a (17 The City should adopt written Design Standards that are followed consistently by City ' staff. 7 (18) he City should improve its enforcement of requirements that are based upon City ordinances or other established laws or regulations. (19) The new City Design Standards should delegate authority to the City Manager or his delegee to make minor modifications to the City Design Standards. I & I (20) Additional guidelines should be established for redevelopment projects, specifically infrastructure guidelines. CONCLUSION Through the team process it became apparent that many of the shortcomings related to the City's development review process can be attributed to the fact that City engineers, located in various departments, have an inconsistent approach to the review of development plans. This inconsistency, rather than intentional, results in part from the fact that each department has its own goal - Development Services to facilitate the development process; Public Works to ensure quality infrastructure for the City, and College Station Utilities to ensure that infrastructure can be adequately maintained. This inconsistency, coupled with the lack of Design Standards, may result in the perception among developers that the City does not support development and contributes to the developers' frustration with the review process. Organizing City engineering positions from each department in one autonomous department reporting directly to City management should help promote consistent application of City Design Standards to the development review process. Early in the Cl team's review we also identified a lack of communication between the departments involved in development review. The first step towards better communication took place during the team's many meetings when team members from different departments repeatedly discussed their roles in the development review process, with each gradually realizing that they could work together to achieve their common goal. This commitment to change is manifested in the staffs' intention to meet regularly to foster an environment of collaboration, rather than dissension, in the development review process. 3