(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. 

 1186-1 
Rule 1186 (cont.) (Amended July 11, 2008) 

(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, 

1186-2 
Rule 1186 (cont.) (Amended July 11, 2008) 

municipal or any 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 winddriven 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 

1186-3 
Rule 1186 (cont.) (Amended July 11, 2008) 

unpaved 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 

1186-4 
Rule 1186 (cont.) (Amended July 11, 2008) 

State Highway and Transportation Officials (AASHTO) guidelines or the 

applicable equivalent 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 

1186-5 
Rule 1186 (cont.) (Amended July 11, 2008) 

(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 

(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 roadbase 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). 

1186-6 
Rule 1186 (cont.) (Amended July 11, 2008) 

(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 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. 

1186-7 
Rule 1186 (cont.) (Amended July 11, 2008) 

(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. 

(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 

1186-8 
Rule 1186 (cont.) (Amended July 11, 2008) 

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. 

(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. 

1186-9 
Rule 1186 (cont.) (Amended July 11, 2008) 

(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. 

(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 

1186-10 
Rule 1186 (cont.) (Amended July 11, 2008) 

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. 

1186-11