NR 110.15(4)(c)
(c) Hydraulic loading. The design wastewater flow shall be estimated in accordance with s.
NR 110.09 (2) (j). When flow or water use records do not exist, the maximum hour design flow shall be estimated by multiplying the average design flow by the appropriate peaking factor shown in Table 2.
NR 110.15(5)(a)(a) Design of conduits. All piping and channels shall be designed to carry the peak design flow rate. The incoming sewer should be designed for unrestricted flow. Bottom corners of the channels must be filleted. Conduits shall be designed to avoid creation of pockets and corners where solids can accumulate. Suitable gates shall be placed in channels to seal off unused sections in which solids might accumulate. The use of shear gates or stop planks may be used in place of gate valves or sluice gates.
NR 110.15(5)(b)
(b) Arrangement of units. Component parts of the facility shall be arranged for greatest operating and maintenance convenience, flexibility, economy, continuity of effluent quality, and ease of installation of future units.
NR 110.15(5)(c)
(c) Flow measurement. Equipment for flow measurement and recording shall be provided for the total waste flow. Equipment for measuring flow streams within the treatment facility should be provided to aid facility operation.
NR 110.15(5)(d)
(d) Emergency operation. At least one of the following shall be provided to ensure continued operation of the sewage treatment facility in accordance with s.
NR 210.08:
NR 110.15(5)(d)1.
1. `Emergency power generator.' An emergency power generator with sufficient generating capacity to meet the sewage treatment facility power demands to comply with s.
NR 210.08.
NR 110.15(5)(d)2.
2. `Two independent electrical transmission sources.' An electrical system connected to two independent transmission routes that receive power from the same electrical grid network which supplies power to the sewage treatment facility service area.
NR 110.15(5)(d)3.
3. `Holding facilities.' Holding facilities that have a capacity to detain the maximum day design flow for a maximum period of 24 hours.
NR 110.15(5)(e)
(e) New processes, methods and equipment. The department encourages the development of new process, methods, or equipment for the treatment of sewage. However, where new processes, methods, or equipment are proposed and where limited data is available which demonstrates the performance of the equipment, the department may require written certification that the use or design of the equipment is in accordance with the manufacturer's guidelines. Furthermore, the department may require the posting of a performance bond by the manufacturer.
NR 110.15(5)(f)
(f) Disinfection. Disinfection shall be provided in accordance with WPDES permit requirements.
NR 110.15(5)(g)
(g) Controlled diversion structures and equipment. Structures and equipment to enable controlled diversions shall be located and arranged to allow for proper maintenance of the sewage treatment facility. In all cases, it must be possible for each treatment unit to be independently removed from service.
NR 110.15 Note
Note: Section
NR 205.07 (1) (u) 2. contains specific provisions associated with the use of controlled diversion structures and equipment and requires compliance with all permit effluent limitations during times of controlled diversion.
NR 110.15(5)(h)
(h)
Sewage treatment facility overflow structures. Sewage treatment facility overflow structures may be provided at an owner's discretion as a measure to protect sewage treatment facility integrity and treatment efficiency during severe operating conditions. Sewage treatment facility overflow structures may not be installed at the headworks of aerated or stabilization pond treatment systems. Sewage treatment facility overflow structures shall be designed in accordance with all the following requirements:
NR 110.15(5)(h)1.
1. The overflow may be activated by either manual or automatic means. If automatically activated, a monitoring system shall be provided to detect the initiation time of the overflow and to provide an alarm signal to the sewage treatment facility operator or other responsible authority.
NR 110.15(5)(h)2.
2. The structure shall be designed to discharge only those wastewater flows above the peak flow rate that the sewage treatment facility can safely process without threatening loss of life, causing severe property damage, or compromising treatment processes, including the washout of biological media in the biological treatment process.
NR 110.15(5)(h)3.
3. Equipment shall be provided to measure the flow and sample the wastewater that is discharged from the structure.
NR 110.15 Note
Note: A department approval of a sewage treatment facility overflow structure does not eliminate or alleviate the requirement that prohibits sewage treatment facility overflows in s.
NR 210.21.
NR 110.15(5)(i)1.1. The use of paints containing lead is prohibited. In order to facilitate the identification of piping, pipes shall be painted as follows:
NR 110.15(5)(i)1.g.
g. Nonpotable water line—blue with 15 centimeter (6 inch) red bands spaced 76 centimeters (30 inches) apart.
NR 110.15(5)(i)2.
2. In addition to the color code, each pipe shall be adequately labeled with a minimum of 2 labels in each room, crawl space or compartment.
NR 110.15(5)(i)3.
3. Existing treatment facilities which do not comply with the provisions of this subsection shall bring the facility into compliance at the time of any major upgrading or expansion of the facility.
NR 110.15(5)(j)
(j) Valve identification. All valves shall be identified in the plans and specifications and labeled during construction.
NR 110.15(5)(k)
(k) Operational considerations. All necessary tools and accessories for the facility operator's use shall be provided. Storage space and a work area shall also be provided. All equipment shall be located as to provide sufficient clearance for proper and convenient maintenance. All tanks, wet wells, channels and pipe systems shall be equipped with drains, valves, or sumps to facilitate draining for maintenance and repair.
NR 110.15(5)(L)
(L) Laboratory space and equipment. A treatment facility owner shall either include a laboratory for making the necessary analytical determinations and operating control tests, or contract with a neighboring facility or independent laboratory to have the analytical and operating control tests done.
NR 110.15(5)(m)
(m) Floor slope. Floor surfaces shall be sloped adequately to a point of drainage.
NR 110.15(5)(n)
(n) Erosion control during construction. Effective site erosion control shall be provided during construction. Project specifications shall detail erosion control methods. Manner of spoil material disposal shall also be detailed.
NR 110.15(5)(o)
(o) Construction materials. Materials shall be selected that are compatible with the wastewater characteristics. Dissimilar metals should be avoided to minimize galvanic action.
NR 110.15(5)(p)
(p) Sanitary facilities. Toilet, shower, lavatory, and locker facilities should be provided in sufficient numbers and convenient locations to serve the expected facility personnel. Toilet, shower, and lavatory facilities shall be provided in the following instances:
NR 110.15(5)(p)1.
1. Any sewage treatment facility equipped with laboratory facilities;
NR 110.15(5)(p)2.
2. Any sewage treatment facility equipped with a potable water supply; or
NR 110.15(5)(p)3.
3. Any sewage treatment facility which has one or more full time operating personnel.
NR 110.15(5)(q)1.1. Sewage treatment facilities shall be enclosed with a fence to discourage entry of animals or unauthorized persons.
NR 110.15(5)(q)2.
2. Hand rails shall be installed around all treatment tanks and in other areas of the facility where the potential of falling exists.
NR 110.15(5)(q)3.
3. The department recommends the following safety measure be considered in the design of wastewater treatment facilities:
NR 110.15(5)(q)3.c.
c. Provision of protective clothing and equipment such as gas masks, goggles, gloves, hard hats, and safety harness;
NR 110.15(5)(q)4.
4. The safety and health rules set forth in ch.
SPS 332, and appropriate federal and local safety codes shall be adhered to in the operation of wastewater treatment plants.
NR 110.15(6)(a)(a) Potable supply. Any sewage treatment facility which has a laboratory shall be provided with a potable water supply.
NR 110.15(6)(b)
(b) Plumbing. Sewage treatment facility plumbing systems shall be designed in accordance with ch.
SPS 382.
NR 110.15(6)(c)
(c) Connection to public water systems. Connection of a sewage treatment facility plumbing system to a public water system shall comply with the requirements of s.
NR 811.25 and ch.
SPS 382.
NR 110.15(6)(d)
(d) On-site wells. Construction of wells for supplying water to a sewage treatment facility shall comply with the requirements of the approval obtained under s.
NR 812.09 (4) (b).
NR 110.15 History
History: Cr.
Register, November, 1974, No. 227, eff. 12-1-74; r. and recr. (1) (c),
Register, March, 1978, No. 267, eff. 4-1-78; r. and recr.
Register, February, 1983, No. 326, eff. 3-1-83, cr. (4) (d),
Register, November, 1990, No. 419, eff. 12-1-90; corrections in (5) and (6) made under s. 13.93 (2m) (b) 7., Stats.,
Register, September, 1995, No. 477; corrections in (5) (q) 4., (6) (b), and (c) were made under s. 13.93 (2m) (b) 7., Stats.,
Register, May, 2001, No. 545;
CR 09-123: am. (2) (a) and (4) (c), cr. (3) (e)
Register July 2010 No. 655, eff. 8-1-10; corrections in (5) (q) 4., (6) (b) and (c) made under s. 13.92 (4) (b) 7., Stats.,
Register January 2012 No. 673;
CR 12-027: r. (2) (c) to (e), r. and recr. (5) (d), am. (5) (g), r. and recr. (5) (h)
Register July 2013 No. 691, eff. 8-1-13;
CR 18-095: am. (6) (d)
Register June 2020 No. 774, eff. 7-1-20; correction in (6) (b) made under s. 35.17, Stats.,
Register June 2020 No. 774.
NR 110.16(1)(a)
(a) Applicability. All wastewater treatment plants shall be provided with protection for pumps and other equipment by installing coarse screens, bar racks, mechanically cleaned bar racks or comminutors.
NR 110.16(1)(b)1.1. Screening devices installed in a building where other equipment or offices are located shall be separated from the rest of the building and provided with separate outside entrances.
NR 110.16(1)(b)3.
3. Screening devices may not be located such that changes in backwater elevations will interfere with the accuracy of upstream flow measuring equipment.
NR 110.16(1)(d)1.1. The channel preceding and following the screen shall be shaped to minimize settling of solids. Fillets shall be installed as necessary.
NR 110.16(1)(d)2.
2. The screen channel invert must be at least 8 centimeters (3 inches) below the invert of the incoming sewer.
NR 110.16(1)(d)3.
3. Where multiple screening units are installed the channels shall be equipped with the necessary gates to direct flow from any one screening unit. Methods for dewatering each channel shall be provided.
NR 110.16(1)(d)4.
4. Entrance channels shall be designed to distribute flow uniformly to the screening units.
NR 110.16(1)(e)
(e) Handling screenings. Adequate facilities must be provided for removal, handling and storage of screenings in a sanitary manner. Hand-cleaned screening facilities must include an accessible platform from which the operator may rake screenings. Suitable drainage facilities must be provided for both the platform and the storage areas.
NR 110.16(2)(a)1.1. Clear spacing between bars may not be less than 2.5 centimeters (1 inch), nor more than 5 centimeters (2 inches).
NR 110.16(2)(a)2.
2. Bar screens must be placed on a slope of 30 to 45 degrees with the horizontal with the exception of those installed for emergency use.
NR 110.16(2)(a)3.
3. Approach velocities may be no less than 38 centimeters per second (1.25 feet per second) at design average flow conditions to prevent settling, and no greater than 91 centimeters per second (3 feet per second) at maximum design daily flow to prevent forcing material through the openings.
NR 110.16(2)(b)1.1. Maximum clean spacing between bars may not exceed 5 centimeters (2 inches).
NR 110.16(2)(b)2.
2. Approach velocities may be no less than 38 centimeters per second (1.25 feet per second) at average design flow conditions to prevent settling, and no greater than 91 centimeters per second (3 feet per second) at maximum daily flow to prevent forcing material through the openings.
NR 110.16(2)(b)3.
3. All mechanical units which are operated by timing devices shall be provided with auxiliary controls which will set the cleaning mechanism in operation at a preset high water elevation.
NR 110.16(2)(b)4.
4. Automatic controls shall be supplemented by a manual override. Manual overrides shall be located in view of the equipment.
NR 110.16(2)(b)5.
5. Electrical fixtures and controls in screening areas where hazardous gases may accumulate shall meet the requirements of the national electrical code for class 1, group D, division 1 locations.
NR 110.16(2)(c)1.1. Comminutors shall be designed to comminute the maximum design flow rate.
NR 110.16(2)(c)2.
2. Comminutor channels shall be designed to contain the upstream water depth associated with the head loss which occurs at maximum design flow without surcharging the incoming sewer or other treatment processes. The expected head loss shall take into account the effects of clogging during operation.
