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(Adopted February 14, 1997)(Amended December 11, 1998)

(Amended September 10, 1999)(Amended April 2, 2004)

(Amended July 11, 2008)

RULE 1186. PM10 EMISSIONS FROM PAVED AND UNPAVED ROADS, 

AND LIVESTOCK OPERATIONS

(a) Purpose

The purpose of this rule is to reduce the amount of particulate matter entrained in the 

ambient air as a result of vehicular travel on paved and unpaved public roads, and at 

livestock operations.

(b) Applicability

The provisions of this rule shall apply to specified land uses and activities conducted 

within the South Coast Air Quality Management District which result in fugitive dust.

(c) Definitions

(1) AVERAGE DAILY TRIPS (ADT) means the average number of vehicles that 

cross a given surface during a specified 24-hour time period as determined by 

the most recent Institute of Transportation Engineers trip generation manual, 

tube counts, or observations. 

(2) CERTIFIED STREET SWEEPER is a sweeper that has been certified by the 

District as meeting the Rule 1186 sweeper certification procedures and

requirements for PM10-efficient sweepers. 

(3) CHEMICAL STABILIZERS mean any non-toxic chemical dust suppressant 

which must not be used if prohibited for use by the Regional Water Quality 

Control Boards, the California Air Resources Board, the U.S. Environmental 

Protection Agency (U.S. EPA), or any applicable law, rule or regulation. The 

chemical stabilizers shall meet any specifications, criteria, or tests required by 

any federal, state, or local water agency. Unless otherwise indicated, the use of 

a non-toxic chemical stabilizer shall be of sufficient concentration and

application frequency to maintain a stabilized surface.

(4) CHEMICAL STABILIZATION means a method of dust control implemented 

by a person to mitigate fugitive dust and corresponding PM10 emissions which 

involves the use of non-toxic chemical stabilizers in sufficient quantities to

maintain a stabilized surface. 
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(5) CONTRACT DATE is the date the contract has been signed by both parties 

but no earlier than 6 months before sweeping begins. Renewals of sweeping 

contracts are considered new contracts.

(6) DISTRICT’S TEST PROTOCOL: RULE 1186 CERTIFIED STREET

SWEEPER COMPLIANCE TESTING means the reference test method

contained in Appendix A, or hereafter approved by the Executive Officer and 

the U.S. Environmental Protection Agency to be an equivalent method.

(7) DUST SUPPRESSANTS are water, hygroscopic materials, or non-toxic 

chemical stabilizers used as a treatment material to reduce fugitive dust

emissions.

(8) ESSENTIAL PUBLIC SERVICES are sewage treatment facilities, prisons, 

police facilities, fire fighting facilities, schools, hospitals, landfills, and water 

delivery operations.

(9) FEED LANE ACCESS AREAS are roads providing access from the feed 

preparation areas to and including feed lane areas at a livestock operation. 

These access roads are typically used to distribute feed from feed trucks to the 

animals.

(10) FUGITIVE DUST means any solid particulate matter that becomes airborne, 

other than that emitted from an exhaust stack, directly or indirectly as a result of 

the activities of man.

(11) INDEPENDENT TESTING FACILITY (OR LABORATORY) means a

testing facility that meets the requirements of District Rule 304, subdivision (k) 

and is approved by the District to conduct certification testing under the 

District’s Test Protocol: RULE 1186 Certified Street Sweeper Compliance 

Testing.

(12) LIVESTOCK OPERATIONS means any operation directly related to the 

raising of more than 50 animals for the primary purpose of making a profit or for 

a livelihood.

(13) OWNER/OPERATOR is any person who owns, leases, or operates a land use 

or activity subject to the requirements of this rule.

(14) PAVED ROAD means a public or private improved street, highway, alley, 

public way, or easement that is covered by typical roadway materials, but

excluding access roadways that connect a facility with a public paved roadway 

and are not open to through traffic. Public paved roads are those open to 

public access and that are owned by any federal, state, county, municipal or any 
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other governmental or quasi-governmental agencies. Private paved roads are 

any paved roads not defined as public.

(15) PM10 is particulate matter with an aerodynamic diameter smaller than or equal 

to 10 microns as measured by the applicable State and Federal reference test 

methods.

(16) PURCHASE OR LEASE DATE is the date the purchase or lease contract for 

delivery of sweeping equipment has been signed by both parties. Renewals of 

leasing contracts are considered new leases.

(17) ROUTINE STREET SWEEPING is street sweeping performed by local

governments or their contractors at least once every three months for a given 

paved road. 

(18) SOUTH COAST AIR BASIN means the non-desert portions of Los Angeles, 

Riverside, and San Bernardino counties and all of Orange County as defined in 

California Code of Regulations, Title 17, Section 60104. The area is bounded 

on the west by the Pacific Ocean, on the north and east by the San Gabriel, San 

Bernardino, and San Jacinto Mountains, and on the south by the San Diego 

county line. 

(19) STABILIZED SURFACE means any previously disturbed surface area or 

open storage pile which, through the application of dust suppressants, shows 

visual or other evidence of surface crusting and is resistant to wind-driven 

fugitive dust.

(20) STREET CLEANING means the removal of post-event visible roadway

accumulations using street sweeping equipment, front end loaders, haul vehicles, 

manual shoveling, street flushing, or any other methods determined effective by 

the responsible agency.

(21) TYPICAL ROADWAY MATERIALS means concrete, asphaltic concrete, 

recycled asphalt, asphalt or any other material of equivalent performance as 

determined by the Executive Officer, the California Air Resources Board, and 

the U.S. EPA.

(22) UNPAVED ACCESS CONNECTIONS means any unpaved road connection 

with a paved public road.

(23) UNPAVED ALLEY means any roadway not exceeding 25 feet in width, which 

is primarily used for access to the rear or side entrances of abutting property, 

and that is not covered by typical roadway materials. 

(24) UNPAVED ROADS are any unsealed or unpaved roads, equipment paths, or 

travel ways that are not covered by typical roadway materials. Public unpaved 
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roads are any unpaved roadway owned by federal, state, county, municipal or 

other governmental or quasi-governmental agencies. Private unpaved roads are 

all unpaved roadways not defined as public. This definition excludes horse 

trails, hiking paths, bicycle paths, or other similar pathways used exclusively for 

purposes other than travel by motorized vehicles.

(25) VISIBLE ROADWAY ACCUMULATIONS means the deposit of particulate 

matter onto paved roads as a result of wind or water erosion, haul vehicle 

spillage, or any other event excluding vehicular track-out, which results in the 

accumulation of visible roadway dust covering a contiguous area in excess of 

200 square feet.

(26) WIND-DRIVEN FUGITIVE DUST means visible emissions from any

disturbed surface area which is generated by wind action alone.

(d) Requirements

Paved Roads

(1) Any owner or operator of a paved public road on which there is visible

roadway accumulations shall begin removal of such material through street

cleaning within 72 hours of any notification of the accumulation and shall

completely remove such material as soon as feasible. If removal cannot be 

completed within 10 days of notification, the owner/operator shall notify the 

Executive Officer and provide information on the location of the accumulation(s) 

and estimated removal completion date.

(2) Any government or government agency which contracts to acquire street

sweeping equipment or street sweeping services for routine street sweeping on 

public roads that it owns and/or maintains, shall acquire or use only certified 

street sweeping equipment. 

(3) Any government or government agency subject to the requirements of

paragraph (d)(2) and/or its contractors shall operate and maintain the certified 

street sweeping equipment in accordance with the manufacturer’s specifications. 

The use of parts determined by the Executive Officer to be substantially similar 

under the provisions of paragraph (f)(4) shall not be deemed a violation of this 

subparagraph.

(4) Beginning January 1, 2006, any owner or operator of a public or private paved 

road shall construct, or require to be constructed, all new or widened paved 

roads in accordance with the American Association of State Highway and 

Transportation Officials (AASHTO) guidelines or the applicable equivalent
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locally adopted guidelines for curbing, width of shoulders, and medians as 

specified below:

(A) New construction or widening of paved roads with projected average 

daily trips of 500 vehicles or more shall be constructed with curbs or as 

an alternative paved outside shoulders using typical roadway materials 

and having the following minimum widths:

Average Daily Trips Minimum Shoulder Width

500 - 3,000 4 feet

3,000 or greater 8 feet

(B) New construction or widening of paved roads with medians and

projected average daily trips of 500 vehicles or more shall pave the 

median area with typical roadway materials unless:

(i) the speed limits are set at or below 45 miles per hour; or 

(ii) the medians are landscaped and maintained with grass or other 

vegetative ground cover and are surrounded by curbing; or

(iii) the medians are treated with chemical stabilizers in sufficient 

quantity and frequency to establish a stabilized surface and are 

surrounded by curbing.

Unpaved Roads

(5) Any owner or operator of an unpaved public road in the South Coast Air Basin 

shall annually treat unpaved roads that have greater than the average ADT of all 

unpaved roads in its jurisdiction (as determined by the owner/operator)

beginning January 1, 1998 and each of the 8 calendar years thereafter by either:

(A) Paving at least 1 mile of such roads using typical roadway

materials; or

(B) Applying chemical stabilization to 2 miles of such roads in

sufficient quantities to maintain a stabilized surface; or

(C) Taking one or more of the following actions on 3 miles of such 

roads:

(i) Installing signage at 1/4 mile intervals that prohibits

vehicular speeds in excess of 15 miles per hour (mph) 

as authorized by California Vehicle Code section

22365 and/or

(ii) Installing speed control devices (e.g., speed bumps)

every 500 feet and/or
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(iii) Maintaining the roadway in such a manner that inhibits 

vehicular speeds in excess of 15 mph.

(Note: Treatment in excess of the annual requirement can be credited toward 

future year requirements.)

Livestock Operations

(6) Any owner or operator of a livestock operation shall cease all hay grinding 

activities between 2:00 and 5:00 p.m. each day, if visible emissions extend more 

than 50 feet from a hay grinding source.

(7) Any owner or operator of a livestock operation shall treat all unpaved access 

connections and unpaved feed lane access areas with either pavement, gravel 

(maintained to a depth of four inches), or asphaltic road-base no later than 

January 1, 1998.

(e) Street Sweeper Testing and Certification Procedures

(1) Any manufacturer seeking certification of street sweeping equipment as a

certified street sweeper shall utilize the following procedures;

(A) The manufacturer shall submit a signed and dated certification request to 

the Executive Officer, and attest to the accuracy of all statements

therein, that shall include:

(i) the name and address of the manufacturer, the brand name, the 

model number, and a complete description of the sweeper’s 

dust collection and suppression system by submitting all of the 

information in paragraph (f)(2); and

(ii) confirmation that the specific sweeper configuration to be

certified has been tested in accordance with District’s Test

Protocol: Rule 1186 Certified Street Sweeper Compliance 

Testing by an independent test facility or laboratory, and that 

test results demonstrate that the sweeper meets the Rule 1186 

sweeper certification limits specified in paragraph (e)(2).

(B) Manufacturers of certified street sweeping equipment may submit a 

certification request for additional equipment that has substantially 

similar material collection and dust suppression system(s) as equipment 

that was certified under the provisions of paragraph (e)(2), by providing 

the information specified in clause (e)(1)(A)(i). If the Executive Officer 

determines that the information submitted by the manufacturers in
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support of an equivalency determination and previous certification test 

results are sufficient to certify the additional equipment, the Executive 

Officer will approve the request.

(2) The Executive Officer will certify street sweeping equipment provided such

equipment meets the following conditions based on a single certification test:

(A) The pick-up efficiency, as defined in the District’s Test Protocol: Rule 

1186 Certified Street Sweeper Compliance Testing, is greater or equal 

to 80 percent; and

(B) The normalized mass of entrained PM10, as defined by District’s Test 

Protocol: Rule 1186 Certified Street Sweeper Compliance Testing, is 

less than or equal to 200 mg/m.

(f) Street Sweeper Performance Characteristics

(1) Any manufacturer of a street sweeper that has previously been certified under 

the provisions of subdivision (e) shall, no later than November 11, 2008, submit 

to the Executive Officer a complete description of the dust collection and 

suppression systems of the equipment as configured during the certification 

testing or as otherwise certified under the provisions of subparagraph (e)(1)(B). 

(2) The description of the dust collection and suppression systems required under 

paragraph (f)(1) shall, at a minimum, consist of the following:

(A) Dust collection 

(i) Gutter broom

(I) material composition;

(II) bristle count and weight;

(III) tensile strength expressed as pounds per square inch

(PSI); and

(IV) dimensions including length, thickness, and width. 

(ii) Main pickup broom (if part of the original certified street

sweeper)

(I) material composition and pounds of fiber per broom;

(II) tensile strength expressed as PSI; and

(III) dimensions including length, thickness, and width.

(iii) Blower/Vacuum system (if part of the original certified street 

sweeper)

(I) horsepower; and

(II) drive type. 
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(B) Dust suppression

(i) Water suppression

(I) schematic drawing showing water nozzle locations and 

orifice nozzle sizes; and 

(II) minimum system relief valve setting for water pump

expressed as pounds per square inch (PSI).

(ii) Filter-based suppression

(I) filter media type and surface area; and

(II) filtration cleansing system, including mechanism and

frequency. 

(3) Any manufacturer of street sweeping equipment shall notify the Executive 

Officer through submission of a plan regarding any change to a part specification 

or part supplier submitted pursuant to paragraph (f)(2). Street sweeping

manufacturers shall be required to submit sufficient specifications and other data 

as determined by the Executive Officer to demonstrate that the equipment 

performance has not been affected by the change of a part specification or part 

supplier prior to the continued distribution of equipment as a certified street 

sweeper. In the event the Executive Officer determines that the certification of 

performance is not maintained, the manufacturer shall lose equipment

certification for the specific street sweeper.

(4) Any street sweeper parts supplier may sell parts to an entity required to procure 

certified street sweeping equipment provided that:

(A) such parts were installed on equipment that was certified under the 

provisions of subdivision (e). Documentation that a given part was on a 

street sweeper during certification testing must be submitted to the

Executive Officer as a plan and must include the following:

(i) Invoices from the parts supplier to the manufacturer, or

(ii) Contractual agreements between the parts supplier to the

manufacturer, or

(iii) Any other documentation that the Executive Officers deems 

sufficient to demonstrate that a given part was on a piece of 

equipment that was previously certified; or

(B) the supplier submits a plan that demonstrates to the satisfaction of the

Executive Officer that the replacement part is substantially similar to the 

original equipment manufacturer part.
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(5) Any person subject to the plan submittal requirements under paragraphs (f)(3) 

or (f)(4) shall be assessed applicable filing and evaluation fees pursuant to Rule 

306 (Plan Fees).

(6) Any plan submitted under the requirements under paragraphs (f)(3) or (f)(4) 

shall be either approved, conditionally approved or disapproved in writing by

the Executive Officer within 120 days of the receipt of a complete plan.

(g) Recordkeeping

(1) Any person subject to paragraph (d)(3) shall maintain operational and

maintenance records demonstrating compliance with paragraph (d)(3). Such 

records for the previous two years of operation (or total period of operation, if 

less than two years) must be made available to the Executive Officer upon

request.

(2) Any person subject to paragraph (d)(5) shall maintain records that document 

compliance with the requirements specified in paragraph (d)(5). Such records 

must be updated annually and must be made available to the Executive Officer 

upon request. 

(h) Exemptions

(1) The provisions of this rule shall not apply to essential public services that are in 

compliance with District Rule 403 (Fugitive Dust). 

(2) The provisions of paragraph (d)(1) shall not apply to:

(A) visible roadway accumulations that occur on roads with fewer than 500 

average daily trips.

(B) paved roads that have been closed until such time that the road is again 

opened to vehicular activity.

(C) events of such magnitude that a State of Emergency has been declared 

by the Governor, provided that removal of visible roadway

accumulations associated with such events are initiated and completed 

as soon as feasible. 

(3) The provisions of paragraph (d)(5) shall not apply to:

(A) any unpaved road 3,000 feet above mean sea level with fewer than 500 

ADT.

(B) any unpaved road used for emergency fire or flood protection or

emergency maintenance of essential service utilities to provide

electricity, natural gas, telephone, water, and sewer.
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(C) any unpaved public road where public access is prohibited.

(D) any unpaved alley.

(E) any government agency if it: 

(i) notifies the Executive Officer that it has less than 5 miles of

unpaved road mileage and implements once at least one of the 

control strategies identified in either subparagraph (d)(5)(A) or 

(d)(5)(B) or (d)(5)(C) on the unpaved road mileage with

greater than the average ADT (as determined by the

owner/operator) by January 1, 2000; or

(ii) notifies the Executive Officer that it has more than 5 but less 

than 10 miles of unpaved road mileage and implements at least 

one of the control strategies identified in either subparagraph 

(d)(5)(A) or (d)(5)(B) or (d)(5)(C) on unpaved roads with

greater than the average ADT (as determined by the

owner/operator) in each three year period beginning January 1,

1998 (with final treatments completed by December 31, 2005); 

or

(iii) notifies the Executive Officer that all of its remaining unpaved 

roads have 20 ADT or less (as determined by the

owner/operator).

(4) The provisions of paragraphs (d)(6) and (d)(7) shall not apply to livestock 

operations whose contiguous bounded areas do not exceed ten acres. 

(5) The provisions of subparagraph (d)(4)(A) shall not apply to unpaved road 

shoulders provided that the area extending eight feet from the outside edge of 

the pavement is landscaped and maintained with grass or other vegetative 

ground cover.

(i) Alternative Control Options

In lieu of complying with the provisions of paragraphs (d)(5) and (d)(7), a person may 

submit for approval by the Executive Officer and the U.S. Environmental Protection 

Agency a plan for achieving equivalent emissions reductions through alternative control 

measures.