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Municipal Code

CHAPTER 1228 Engineering Design Standards

1228.01 Title.
1228.02 Purpose.
1228.03 General requirements.
1228.04 Sanitary sewers; pressure sewers.
1228.05 Storm sewers and storm water retention/detention.
1228.06 Water mains.

1228.07 Grading.
1228.08 Compliance required.
1228.09 Fees.
1228.10 Liability insurance; maintenance bonds.
1228.11 Variances.
1228.12 Minimum requirements; conflicts of law.


CROSS REFERENCES
Maintenance of Village utilities - see CHTR. Ch. XIV
Review expenses - see ADM. Ch. 210
Village Engineer - see ADM. Ch. 240
Waste Water Management District - see S.U. & P.S. Ch. 1040
Sewer use and user charges - see S.U. & P.S. Ch. 1042
Planning Commission generally - see P. & Z. Ch. 1220
Subdivision regulations - see P. & Z. Ch. 1225
Board of Zoning Appeals - see P. & Z. Ch. 1244



1228.01 TITLE.
This chapter shall be known and may be cited as the "Village of Franklin Engineering Design Standards."
(Ord. 96-87. Passed 5-13-96.)

1228.02 PURPOSE.
The purpose of this chapter is to provide a reasonable and proper basis for the design and construction of subdivision and other project site improvements, including sanitary sewer, storm sewer and water main improvements and site grading.
(Ord. 96-87. Passed 5-13-96.)



1228.03 GENERAL REQUIREMENTS.
(a) Plans submitted shall be on twenty-four inch by thirty-six inch white prints having blue or black lines and shall be neatly and accurately prepared. Judgment should be exercised in the design, layout and presentation of proposed improvements.

(b) For projects or subdivisions having more than one sheet of plans, a general plan having a scale of one inch equals 100 feet shall be provided showing the overall project or subdivision and indicating the location of all improvements shown in the detailed plans. Street names, lot lines and lot numbers shall be shown in all plans. Easements shall have a minimum width of twelve feet. Sewers in easements shall be kept at least two feet away from side or rear lot lines. Superimposed on this general plan shall be two-foot contours of the area, including the area at least 100 feet outside of the subdivision.

(c) All sewers shall be shown in plan and profile. Profiles of sewers shall indicate the size, invert and slope of the sewer and shall also indicate the existing ground along the route of the sewer and the proposed or existing top of the curb, edge of pavement grade or proposed ground.

(d) Two bench marks shall be provided. Elevations shall be on U.S.G.S. datum. Bench marks for the work shall be indicated on the plan.

(e) Finished grades of structures shall be indicated on the plan or profile for all structures.

(f) A copy of the computed plat shall be submitted where applicable.

(g) All plans submitted shall bear the seal of the registered professional engineer responsible for the design.

(h) One mylar copy of as built plans for water, sanitary sewers, roads and the storm sewer system, and certification from a registered professional engineer that all surface grades, roads and structures are in conformance with the approved plan, shall be provided prior to acceptance of the subdivision improvements by the Village of Franklin.

(i) Complete subdivision improvement plans shall be submitted prior to review and approval of any portion thereof.
(Ord. 96-87. Passed 5-13-96.)



1228.04 SANITARY SEWERS; PRESSURE SEWERS.
(a) Submittal Procedures. For the Village of Franklin's approval of sanitary sewer systems, the applicant shall furnish to the Village a detailed estimate of cost and three sets of the sanitary sewer plans and specifications, including the general plan, for the system for which he or she desires approval. The Village Engineer shall review the estimate and the plans for conformity to the standards set forth herein and certify that they are consistent with the overall utility plans of the Village, after which the Village Engineer will return one of the three sets with appropriate comments. After making any changes requested on the set of plans returned to him or her, the applicant shall then submit eight sets of the revised plans to the Village for final approval. The Village Engineer shall then review these revised plans for conformity to the comments mentioned heretofore, and, if the changes have been properly made, will transmit six copies to the Oakland County Drain Commissioner's office (O.C.D.C.) for its review of the connection details. The O.C.D.C. will then transmit the plans to the Michigan Department of Natural Resources (M.D.N.R.) for a construction permit. An approved copy will be returned to the applicant via the M.D.N.R.

(b) Design Standards.
(1) The following notes pertaining to sanitary sewers shall appear on the plans:
A. All construction shall conform to the current standards and specifications of the local unit of government and the Oakland County Drain Commissioner (O.C.D.C.). All sanitary sewer construction shall have full-time inspection supervised by a professional engineer provided by or caused to be provided by the local unit of government.

B. At all connections to the Oakland County Drain Commissioner's sewers or extensions, and before the start of construction, the contractor must obtain a sewer inspection permit issued by the O.C.D.C. Gravity sewer permit charges are one hundred fifty dollars ($150.00) for each connection, plus fifteen dollars ($15.00) for each manhole constructed. Pressure sewer permit charges are two hundred fifty dollars ($250.00) per 2,460 l.f. of force main, with a minimum permit fee of two hundred fifty dollars ($250.00). Failure to pass any test segment will result in an additional charge to the contractor for each retest, in accordance with the above price schedule. The contractor shall also have posted with the O.C.D.C. a five thousand dollar ($5,000) surety bond and a five hundred dollar ($500.00) cash deposit. The contractor shall notify the local unit of government and the O.C.D.C. twenty-four hours prior to the beginning of any construction. Final air tests must be witnessed by County personnel and must be scheduled in advance.



C. No sewer installation shall have an infiltration exceeding 200 gallons per inch of diameter per mile of pipe in a twenty-four hour period, and no single run of sewer between manholes shall exceed 250 gallons per inch of diameter per mile. Air tests in lieu of infiltration tests shall be as specified in the O.C.D.P.W. "Acceptance Tests," dated September, 1972. Only pipe and pipe joints approved by the Oakland County Drain Commissioner may be used for sanitary sewer construction.
D. At all connections to an existing Oakland County Drain Commissioner sewer, or an extension thereto, a watertight bulkhead with a capped one inch diameter pipe to permit measuring infiltration shall be provided. A temporary twelve inch deep sump shall also be provided in the first manhole above the connection which will be filled in after successful completion of any infiltration test up to the standard fillet provided for the flow channel.
E. All building leads and risers shall be six inch S.D.R. 23.5 ABS pipe with chemically fused joints, or an approved equal pipe and joint. Sewer pipe wye or tee openings shall contain factory installed premium joint material of an approved type compatible with that of the building lead pipe used. Building leads shall be furnished with removable airtight and watertight stoppers.
F. All rigid sewer pipe shall be installed in Class "B" bedding or better. All flexible, semi flexible or composite sewer pipe shall be installed in conformity with Oakland County Drain Commissioner specifications.
G. All new manholes shall have Oakland County Drain Commissioner approved flexible, watertight seals where pipes pass through walls. Manholes shall be of precast sections with modified grooved tongue and rubber gasket-type joints. Precast manhole cone sections shall be Oakland County Drain Commissioner approved modified eccentric cone-type. All manholes shall be provided with bolted, watertight covers.

H. At all connections to manholes on Oakland County Drain Commissioner's sewers, or extensions thereto, drop connections will be required when the difference in invert elevations exceeds eighteen inches. Only outside drop connections will be approved.
I. Taps to existing manholes shall be made by coring. The contractor shall place a KOR N SEAL boot (or O.C.D.C.-approved equal) after coring is completed. Blind drilling will not be permitted in lieu of coring.


J. New manholes constructed directly on Oakland County Drain Commissioner's sewers shall be provided with covers reading "Oakland County Sanitary" in raised letters. New manholes built over an existing sanitary sewer shall have monolithic poured bottoms.
K. No ground water, storm water, construction water, downspout drainage or weep tile drainage shall be allowed to enter any sanitary sewer installation.
L. Prior to any excavation, the contractor shall telephone MISS DIG (647 7344) for the location of underground pipeline and cable facilities, and shall also notify representatives of other facilities located in the vicinity of the work.
M. An eighteen-inch minimum vertical separation and a ten-foot minimum horizontal separation must be maintained between a sanitary sewer and a water main.
(2) Prior to starting any sanitary sewer design, the applicant may make use of maps and information available at the Village of Franklin offices. It shall be the responsibility of the applicant to verify utility locations provided by the Village of Franklin.
(3) The following table of minimum slopes for gravity sanitary sewers shall be adhered to:

Size (in.) and Minimum Slope

10" 0.28
12" 0.22
15" 0.15
18" 0.12
21" 0.10
24" 0.08


NOTE: In the Village of Franklin, for gravity sewers, the minimum allowable size of a sanitary lateral is ten inches in diameter.

(4) A note or detail shall show the type of bedding upon which the sewer pipe shall be installed.

(5) For gravity sewers, the house leads from the lateral sewer to serve the building shall be a minimum of six inches in diameter within the street right of way and shall be extended a minimum of ten feet past the property line. For pressure sewers, the minimum house lead size shall be one and one-quarter inches in diameter.



(6) Sanitary sewer manholes shall be spaced with the following recommended maximums:

Diameter of Sewer (in.) Maximum Manhole Spacing (ft.)
10 300 feet
12 to 21 350 feet
24 and larger 400 feet

Manholes shall be placed in the street right of way. In general, sanitary sewers will not be approved in any rear yard easement. Sanitary sewer manholes shall be of precast construction with modified grooved tongue with rubber gasket.
(7) Grinder pump stations on the pressure sewer system shall meet Village of Franklin and Oakland County standards.
(8) All gravity and pressure sewers shall be profiled. The sewer profile shall indicate the length of run between each manhole, the size and slope of the sewer between each manhole, the class of bedding, in the event that concrete bedding is required, the type of pipe material, invert elevations and the type of backfill. Top elevations of all manholes shall be indicated.
(9) A minimum depth, from the top of the curb (or road centerline) to the top of any sanitary sewer, of eight and one-half feet at local control points, or a minimum of nine feet at locations where the sewer grade is parallel to the road grade, shall be provided for gravity sewers. A minimum depth of cover of five feet shall be provided for pressure sewers. In all cases, gravity sewers shall be deep enough to serve, by gravity, a standard depth basement.
(10) Each wye or end of house connection shall have a plug with the same type of joint as the main sewer. The end of the house lead shall be marked with a wooden two inch by two inch (or equal) stake up to eighteen inches of the ground surface.
(11) Allowable types of sewer pipe and joints shall conform to current Village of Franklin standards and shall be covered on the plans by a note or on the profile, where applicable.
(Ord. 96-87. Passed 5-13-96.)



1228.05 STORM SEWERS AND STORM WATERRETENTION/DETENTION.
(a) Submittal Procedures. For the Village of Franklin's approval of storm sewer systems, the applicant shall furnish to the Village of Franklin a detailed estimate of cost and three sets of plans and specifications. Detailed storm sewer design computations, retention/detention computations, and the drainage area map indicating the various areas going into the points of inlet, shall be provided. The Village Engineer shall review the estimate and the plans for conformity to standards set forth herein and certify that they are consistent with the overall utility plans of the Village of Franklin, after which the Village Engineer will return one of the three sets with appropriate comments. After making any changes requested on the set of plans returned to him or her, the applicant shall then submit three sets of revised plans to the Village of Franklin for final approval. The Village Engineer shall then review these revised plans for conformity to the comments mentioned heretofore, and, if the changes have been properly made, will retain two copies for the Village of Franklin's records and return one approved copy to the applicant. The applicant shall obtain approval of the Oakland County Road Commission and the Oakland County Drain Commissioner, where applicable.

(b) Design Standards for Storm Sewers.
(1) Storm drainage systems shall be designed for a ten-year storm. The rational method for arriving at storm water runoff shall be used.

The formula for rainfall intensity shall be equivalent to the following: I ‘ 175/T + 25

in which T is the time of concentration. The consulting engineer shall use judgment in arriving at proper impervious factors.

The consulting engineer shall submit a map outlining the various areas, including off-site upstream areas, which drain to the points of inlet used for design, together with the storm sewer design computations. In general, sufficient capacity shall be provided in the storm sewer system to take fully developed (fully paved and sewered) upstream drainage into the system.
(2) Where the hydraulic gradient is above the top of the sewer pipe, the design elevation of the hydraulic gradient shall be indicated in the profile view of the proposed storm sewer.



(3) Manhole spacing for storm sewers shall be as follows:

Diameter of Maximum
Sewer (in.) Manhole Spacing (ft.)
10 to 15 330
18 to 30 350
36 and 42 400
48 450
54 and 60 500
66 and larger 600

NOTE: Height of Lo Head pipe shall be used as the criteria for manhole spacing. Catch basins shall not be constructed over a sewer line to replace manholes.
(4) The following information shall be indicated on the storm sewer profile:
A. Length of run between manholes;
B. Size and slope of sewer between manholes;
C. Class of bedding, where concrete is required;
D. Top elevation of all manholes;
E. Type of pipe material; and
F. Backfill material.
Where possible, the slope of the sewers shall provide a minimum velocity of 2.5 feet per second.
(5) A note or detail shall show the type of bedding upon which the sewer pipe shall be installed.
(6) Where possible, a minimum of three feet of cover from the top of the curb (or road centerline) to the top of any storm sewer shall be provided. If the depth of cover to the top of the pipe is less than one foot, C 76 CL 5 pipe shall be used. If the cover is between one foot and three feet from the top of the curb to the top of the pipe, C 76 CL 4 pipe shall be used. All catch basin leads within a street shall be C 76 CL 4 pipe, including the leads to the manholes.
(7) In general, catch basins shall be located as follows:
A. At the radius return of street intersections. A 150-foot maximum distance along the street, between a high point and a corner catch basin, is allowed when drainage is required to go around the corner.
B. At all low points in streets.
C. At intermediate points along the street such that there is a maximum of 600 feet of drainage draining from a high point to a catch basin or from a previous intercepting catch basin to this catch basin.



A maximum of 900 feet of drainage is allowed from two directions.
(8) Field catch basins shall be provided at all low points in easements. Intercepting field catch basins shall be located such that not more than 600 feet of drainage runs into any one catch basin other than at a low point of such catch basin. One thousand, two hundred feet of drainage is allowed to run into a low point of a catch basin. Field catch basins shall be located in rear lot easement swales when such swales changes direction by more than forty-five degrees.
(9) Finished easement grades shall be indicated on the plans.
(10) Improved open drains may be permitted under special circumstances, in accordance with Section 1228.11.
(11) Headwalls and inlet structures shall be placed as required. Bar screens are to be provided on all end sections and pipe ends where the pipe size exceeds fifteen inches in diameter.
(12) Allowable types of sewer pipe and joints shall conform to current Village of Franklin standards and shall be covered on the plan by a note or on the profile, where applicable.
(13) For new subdivisions, lateral storm sewers shall be constructed to provide an outlet for the footing drain discharge house leads. Extensions of storm sewer laterals to provide for footing drain discharge only shall be a minimum of eight inches in diameter on a minimum 0.4 percent grade with manholes spaced a maximum of 300 feet apart.
(14) Wherever sufficient grade is available, storm sewers shall be constructed at a depth adequate to allow for gravity drainage of the building footing drains. Where grading is not available to allow for gravity drainage of the footing drains, a sump pump shall be provided with the sump pump discharge connected to the enclosed storm sewer system. The plans shall clearly state which units require pumped sump outlets.
(15) A minimum four inches diameter storm sewer lead shall be constructed from the lateral storm sewer to the property line to provide an outlet for the footing drain discharge. The lead shall be constructed at a minimum depth of three and one-half feet on a minimum of 1.0 percent grade. The materials and methods of construction shall be in accordance with current Village of Franklin standards.

(c) Design Standards for Retention and Detention Basins. Any new development or addition to an existing development must retain/detain the increased runoff on-site unless otherwise directed by the Village Engineer. Acceptable means of retention/detention can be achieved through standing water in parking areas (to a maximum depth of six inches) or a separate retention/detention basin.



The County method of retention basin design, as available from the County Drain Commissioner's Office, shall be utilized in determining the volume of retention required. Basins with orifice outlets will be required to hold the volume of a ten year storm, while basins with no outlets will be required to hold two consecutive 100 year storms. Discharge through an orifice outlet shall not exceed 0.2 cfs/acre.
(1) Minimum specifications.
A. All man-made open storm water retention/detention basins shall have side slopes no steeper than one vertical to five horizontal.
B. The basin must be constructed to drain entirely, unless it is designed to retain a permanent water level that conforms to the aesthetics of a landscape plan relating to the surrounding landscape.
C. The bottom of the basin must have stable vegetative cover or some other approved method of stabilization.
D. A minimum of twelve inches of freeboard must be maintained with a positive, nonerodible overflow capable of handling the capacity of a 100 year storm.
E. The minimum grade on the bottom of the basin shall be 1.0 percent, where feasible.
(2) Maintenance agreement. A maintenance agreement shall be required for all storm water retention/detention basins.
(Ord. 96-87. Passed 5-13-96.)

1228.06 WATER MAINS.
(a) Submittal procedures. For the Village of Franklin's approval of water main systems, the applicant shall furnish to the Village of Franklin a detailed estimate of cost and three sets of water main plans and specifications for the system for which the applicant desires approval. The Village Engineer shall review the estimate and the plans for conformity to the standards set forth herein and certify that they are consistent with the overall utility plans of the Village, after which the Village Engineer will return one of the three sets with appropriate comments. After making any changes requested on the set of plans returned to him or her, the applicant shall then submit nine sets of revised plans to the Village for final approval. The Village Engineer shall then review these revised plans for conformity to the comments mentioned heretofore, and, if the changes have been properly made, will transmit nine copies to the City of Detroit for approval (when applicable). After City of Detroit approval has been obtained (when applicable), the copies will be forwarded to the Michigan State Health Department for a construction permit.



(b) Design Standards.
(1) The type of pipe and joint shall be in accordance with current Village of Franklin standards.
(2) All water mains shall be installed with a minimum cover of five feet below finished grade. Where water mains must dip to pass under a storm sewer or sanitary sewer, the sections which are deeper than normal shall be kept to a minimum length by the use of vertical eleven and one-quarter degree bends, properly anchored.
(3) The minimum size for Village of Franklin water mains shall be eight inches in diameter. Gate valves shall be located in the system such that not more than four valves need be turned off to isolate any section of water main. Moreover, sufficient valves shall be placed such that not more than thirty lots shall be serviced within such section of water main which can be so isolated. Also, valves shall be placed so that no more than two hydrants are out of service at any one time. Where possible, gate valves shall be located at street intersections five feet from the intersecting street right of way line.
(4) Hydrants shall be installed along the water main at least every 600 feet. In no case shall a house be more than 350 feet from a hydrant. In commercial or industrial districts, additional hydrants may be required. Hydrants shall be installed at the ends of all dead end water mains. When near a street intersection, hydrants shall be located fifteen feet from the intersecting street right of way. Hydrants shall conform to current Village of Franklin standards.
(5) The plans shall indicate the finished grades of all hydrants and gate wells. (Ord. 96-87. Passed 5-13-96.)

1228.07 GRADING.
(a) Submittal Procedures. For the Village of Franklin's approval of a grading plan for erosion and sediment control, the applicant shall furnish a detailed estimate of cost and three sets of the subdivision and/or site grading plans. The Village Engineer shall review the estimate and plans for conformity to the principles set forth herein, after which the Village Engineer will return one of the three sets with appropriate comments. After making any changes requested on the set of plans returned to him or her, the applicant shall then submit four sets of revised plans to the Village for final approval. The Village Engineer shall then review these revised plans for conformity to the comments mentioned heretofore, and, if the changes have been properly made, will retain three copies for the Village records and return one approved copy to the applicant.



(b) Design Standards. In order to provide effective erosion and sediment control, practical combinations of the following technical principles shall be applied to the erosion control aspects of the grading plan. All soil erosion control measures shall be in accordance with Oakland County Drain Commissioner standards and will require permission from the County, where applicable:
(1) The smallest practical area of land should be exposed at any one time during development.
(2) When land is exposed during development, the exposure should be kept to the shortest practical period of time.
(3) Temporary vegetation and/or mulching should be used to protect critical areas exposed during development.
(4) Sediment basins (debris basins or silt traps) should be installed and maintained to remove sediment from runoff waters from land undergoing development.
(5) Provisions should be made to effectively accommodate the increased runoff caused by changed soil and surface conditions during and after development.
(6) The permanent final vegetation and any structures should be installed as soon as practical in the development.
(7) The development plan should be fitted to the topography and soil so as to create the least erosion potential.
(8) Wherever feasible, natural vegetation should be retained and protected.
(Ord. 96-87. Passed 5-13-96.)

1228.08 COMPLIANCE REQUIRED.
The approvals required under the provisions of this chapter shall be obtained prior to the installation of any subdivision or project improvement within the Village of Franklin, in public streets, public alleys, public rights of way and public easements, and/or under the ultimate jurisdiction of the Village, and such subdivision or project improvement shall comply with all of the provisions and requirements of this chapter or any other related ordinance. (Ord. 96-87. Passed 5-13-96.)

1228.09 FEES.
(a) At the time of submittal of plans, specifications and detailed estimates of the cost of proposed subdivision and project improvements, the proprietor shall pay the Clerk a fee for review of the same equal to 1.3 percent of the estimate of the cost of such improvements.

(b) Prior to the construction of subdivision and project improvements, the proprietor shall deposit with the Clerk, at least twenty-four hours prior to the start of construction, a percentage of the total contract price for inspection, as follows:


Contract Amount Percentage or Amount on Deposit
$0 $10,000 $1,000
10,000 50,000 11%
50,000 100,000 9%, or not less than $5,500
100,000 200,000 8%, or not less than $9,000
200,000 300,000 7%, or not less than $16,000
300,000 500,000 5.5%, or not less than $17,000
More than 500,000 4.5%

(c) The actual fee for inspection, which will be supplied on a full-time basis and shall be borne by the proprietor, will be on a payroll cost, plus 100 percent.

(d) The fees and charges herein contained shall be in addition to those charged for debt service charges, connection charges and other charges or fees imposed for sanitary sewers and water supply. (Ord. 96-87. Passed 5-13-96.)

1228.10 LIABILITY INSURANCE; MAINTENANCE BONDS.
Prior to the construction of subdivision and project improvements, the contractor shall procure and maintain, during the life of any contract or agreement for such construction, insurance protecting the Village of Franklin and its consultants from any claim for damages, real, personal or otherwise, in such amounts as established by resolution of the Village of Franklin.
Prior to the acceptance of improvements by the Village of Franklin, a one year maintenance bond equal to 100 percent of the cost of installed utilities (sanitary and storm sewers and water mains) shall be posted by the proprietor.
(Ord. 96-87. Passed 5-13-96.)

1228.11 VARIANCES.
(a) The Village of Franklin may authorize a variance from these engineering design standards when it determines that undue hardship may result from strict compliance. In granting any variance, the Board of Zoning Appeals shall prescribe other conditions that it deems necessary or desirable for the public interest. No variance shall be granted unless the Village of Franklin finds that:
(1) There are special circumstances or conditions affecting the subdivision or project improvement such that a strict application of the provisions of this chapter would deprive the applicant of reasonable use of his property.
(2) The variance is necessary for the preservation and enjoyment of the substantial property right of the applicant.
(3) The granting of the variance will not be detrimental to the public welfare or injurious to other property in the area in which said property is situated.



(b) An application for any such variance shall be submitted in writing by the proprietor at the time the preliminary plans are submitted, stating fully and clearly all facts relied upon by the proprietor, and shall be supplemented with maps, plans or other additional data which may aid in the analysis of the proposed project. The plans for such development shall include such covenants, restrictions or other legal provisions as are necessary to guarantee the full achievement of the plans.
(Ord. 96-87. Passed 5-13-96.)

1228.12 MINIMUM REQUIREMENTS; CONFLICTS OF LAW.
The provisions of these regulations shall be held to be the minimum requirements adopted for the promotion and preservation of the public health, safety and general welfare of the Village of Franklin. These regulations are not intended to repeal, abrogate, annul or in any manner interfere with existing regulations or laws of the Village of Franklin, nor conflict with any statutes of the State of Michigan or Oakland County, except that these regulations shall prevail in cases where these regulations impose a greater restriction than is provided by existing statutes, laws or regulations.
(Ord. 96-87. Passed 5-13-96.)