403.1 - 1 

(Adopted January 15, 1993)(Amended June 16, 2000)(Amended April 2, 2004) 

RULE 403.1. SUPPLEMENTAL FUGITIVE DUST CONTROL 

REQUIREMENTS FOR COACHELLA VALLEY SOURCES 

(a) Purpose 

The purpose of this rule is to reduce or prevent the amount of fine particulate 

matter (PM10) entrained in the ambient air from anthropogenic (man-made) 

fugitive dust sources. 

(b) Applicability 

The provisions of this rule are supplemental to Rule 403 requirements and shall 

apply only to fugitive dust sources in the Coachella Valley. 

(c) Definitions 

(1) ACTIVE OPERATIONS shall mean any source capable of generating 

fugitive dust, including, but not limited to, earth-moving activities, 

construction/demolition activities, disturbed surface areas, or agricultural 

operations. 

(2) AGRICULTURAL OPERATIONS means any operation occurring on a 

ranch or farm directly related to the growing of crops, or raising of fowls 

or animals for the primary purpose of making a profit or for a livelihood. 

(3) ANEMOMETERS are devices used to measure wind speed in accordance 

with the performance standards, maintenance and calibration criteria 

specified in the Rule 403.1 Implementation Handbook. 

(4) BULK MATERIAL is sand, gravel, soil, aggregate material less than two 

inches in length or diameter and other organic and inorganic particulate 

matter. 

(5) CHEMICAL STABILIZERS are 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. 
Rule 403.1 (cont.) (Amended April 2, 2004) 

403.1 - 2 

(6) COACHELLA VALLEY means that portion of Riverside County, as 

defined in Rule 103, subdivision (h). 

(7) COACHELLA VALLEY BLOWSAND ZONE means the corridor of land 

extending two miles to either side of the centerline of the I-10 Freeway 

beginning at the SR-111/I-10 junction and continuing southeast to the I10/ Jefferson Street interchange in Indio. 

(8) CONSTRUCTION/DEMOLITION ACTIVITIES means any on-site 

mechanical activities conducted in preparation of or related to, the 

building, alteration, rehabilitation, demolition or improvement of property, 

including, but not limited to the following activities: grading, excavation, 

loading, crushing, cutting, planing, shaping or ground breaking. 

(9) DISTURBED SURFACE AREA means a portion of the earth's surface 

which has been physically moved, uncovered, destabilized, or otherwise 

modified from its undisturbed natural soil condition, thereby increasing 

the potential for emission of fugitive dust. This definition excludes those 

areas which have: 

(A) been restored to a natural state, such that vegetative ground cover 

and soil characteristics are similar to adjacent or near-by natural 

conditions; 

(B) been paved or otherwise covered by a permanent structure; 

(C) sustained a vegetative ground cover of at least 70 percent of the 

average native cover for a particular area for at least 30 days. 

(10) DUST CONTROL SUPERVISOR means a person with the authority to 

expeditiously employ sufficient dust mitigation measures to ensure 

compliance with all Rule 403 and Rule 403.1 requirements at an active 

operation. 

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

chemical stabilizers used as a treatment material to reduce fugitive 

emissions. 

(12) EARTH-MOVING ACTIVITIES means the use of any equipment for any 

activity where soil is being moved or uncovered and shall include, but not 

be limited to the following: such operations as grading, loading or 

unloading of dirt or bulk materials, adding to or removing from open 

storage piles of bulk materials, landfill operations, weed abatement 

through disking, soil mulching and agricultural tilling. 
Rule 403.1 (cont.) (Amended April 2, 2004) 

403.1 - 3 

(13) 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 any person. 

(14) FUGITIVE DUST CONTROL PLAN means a plan to control fugitive 

dust plan as described in subdivision (e). 

(15) ON-SITE means within the property lines of a property, or as otherwise 

approved by the Executive Officer. 

(16) OPEN STORAGE PILE is any accumulation of bulk material which is not 

fully enclosed, covered or chemically stabilized, and which attains a 

height of three feet or more and a total surface area of 150 or more square 

feet. 

(17) PARTICULATE MATTER means any material, except uncombined 

water, which exists in a finely divided form as a liquid or solid at standard 

conditions. 

(18) PM10 means particulate matter with an aerodynamic diameter smaller than 

or equal to 10 microns as measured by the applicable state and federal 

reference test methods. 

(19) PROPERTY LINE means the boundaries of an area in which a person 

allowing the emission has the legal use or possession of the property. 

Where such property is divided into one or more sub-tenancies, the 

property line(s) shall refer to the boundaries dividing the areas of all subtenancies. 

(20) RULE 403.1 IMPLEMENTATION HANDBOOK means a guidance 

document that has been approved by the Governing Board on April 2, 

2004 or hereafter approved by the Executive Officer and the U.S. EPA. 

(21) STABILIZED SURFACE means any previously disturbed surface area 

which, through the application of dust suppressants, shows visual or other 

evidence of surface crusting and is resistant to wind-driven fugitive dust 

and is demonstrated to be stabilized. Stabilization can be demonstrated by 

one or more of the applicable test methods contained in the Rule 403.1 

Implementation Handbook. 

(22) UNPAVED ROADS means any unsealed or unpaved roads, equipment 

paths, or travel ways that are not covered by one of the following: 

concrete, asphaltic concrete, recycled asphalt, asphalt or other materials 

with equivalent performance as determined by the Executive Officer, the 

California Air Resources Board, and the U.S. EPA. Public unpaved roads 
Rule 403.1 (cont.) (Amended April 2, 2004) 

403.1 - 4 

are any unpaved roadway owned by federal, state, county, municipal or 

other governmental or quasi-governmental agencies. Private unpaved 

roads are all other unpaved roadways not defined as public. 

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

disturbed surface area which is generated by wind action alone. 

(24) WIND GUST is the maximum instantaneous wind speed as measured by 

an anemometer. 

(d) General Requirements 

(1) Any person who is responsible for any active operation, open storage pile, 

or disturbed surface area, and who seeks an exemption pursuant to Rule 

403, paragraph (g)(2) shall be required to determine when wind speed 

conditions exceed 25 miles per hour. The wind speed determination shall 

be based on either District forecasts or through use of an on-site 

anemometer as described in subdivision (g). 

(2) Any person involved in active operations in the Coachella Valley 

Blowsand Zone shall stabilize new man-made deposits of bulk material 

within 24 hours of making such bulk material deposits. Stabilization 

procedures shall include one or more of the following: 

(A) Application of water to at least 70 percent of the surface area of 

any bulk material deposits at least 3 times for each day that there is 

evidence of wind driven fugitive dust; or 

(B) Application of chemical stabilizers in sufficient concentration so as 

to maintain a stabilized surface for a period of at least 6 months; or 

(C) Installation of wind breaks of such design so as to reduce 

maximum wind gusts to less than 25 miles per hour in the area of 

the bulk material deposits. 

(3) Any person involved in active operations in the Coachella Valley 

Blowsand Zone shall stabilize new deposits of bulk material originating 

from off-site undisturbed natural desert areas within 72 hours. 

Stabilization procedures shall include one or more of the following: 

(A) Application of water to at least 70 percent of the surface area of 

any bulk material deposits at least 3 times for each day that there is 

evidence of wind driven fugitive dust; or 

(B) Application of chemical stabilizers in sufficient concentration so as 

to maintain a stabilized surface for a period of at least six months. 
Rule 403.1 (cont.) (Amended April 2, 2004) 

403.1 - 5 

(4) A person who conducts or authorizes the conducting of an active 

operation shall implement at least one of the control actions specified in 

Rule 403, Table 2 for the source category "Inactive Disturbed Surface 

Areas" to minimize wind driven fugitive dust from disturbed surface areas 

at such time when active operations have ceased for a period of at least 20 

days. 

(5) Any person involved in agricultural tilling or soil mulching activities shall 

cease such activities when wind speeds exceed 25 miles per hour. The 

wind speed determination shall be based on either District forecasts or 

through use of an on-site anemometer as described in subdivision (g). 

(e) Fugitive Dust Control Plan and Other Requirements for Construction 

Projects/Earth-Moving Activities 

(1) Any person who conducts or authorizes the conducting of an active 

operation with a disturbed surface area of more than 5,000 square feet 

shall not initiate any earth-moving activities unless a fugitive dust control 

plan is prepared and approved by the Executive Officer in accordance with 

the requirements of subdivision (f) and the Rule 403.1 Implementation 

Handbook. These provisions shall not apply to active operations 

exempted by paragraph (i)(4). 

(2) Any operator required to submit a fugitive dust control plan under 

paragraph (e)(1) shall maintain a complete copy of the approved fugitive 

dust control plan on site in a conspicuous place at all times and the 

fugitive dust control plan must be provided upon request. 

(3) Any operator required to submit a fugitive dust control plan under 

paragraph (e)(1) shall install and maintain signage with project contact 

information that meets the minimum standards of the Rule 403.1 

Implementation Handbook prior to initiating any type of earth-moving 

activities. 

(4) Any operator required to submit a fugitive dust control plan under 

paragraph (e)(1) for a project with a disturbed surface area of 50 or more 

acres shall have an Dust Control Supervisor that: 

(A) is employed by or contracted with the property owner or 

developer; and 

(B) is on-site or is available to be on-site within 30 minutes of initial 

contact; and 
Rule 403.1 (cont.) (Amended April 2, 2004) 

403.1 - 6 

(C) has the authority to expeditiously employ sufficient dust mitigation 

measures to ensure compliance with all Rule 403 and 403.1 

requirements; and 

(D) has completed the AQMD Coachella Valley Fugitive Dust Control 

Class and has been issued a valid Certificate of Completion for the 

class. 

(5) Failure to comply with any of the provisions of an approved fugitive dust 

control plan shall be a violation of this rule. 

(f) Fugitive Dust Control Plan Preparation, Submittal, and Approval Requirements 

(1) A fugitive dust control plan prepared pursuant to paragraph (e)(1) must 

include the following information in a 8 1⁄2 by 11 inch format: 

(A) the name(s), address(es), and phone number(s) of the person(s) 

responsible for the preparation, submittal, and implementation of 

the fugitive dust control plan; and 

(B) a description of the operation(s), including a map depicting the 

location of the site; and 

(C) a listing of all sources of fugitive dust emissions within the 

property lines; and 

(D) a description of the control measures as identified by the Rule 

403.1 Implementation Handbook as applied to each of the sources 

identified in the fugitive dust control plan. The description of the 

control measures must be sufficiently detailed to demonstrate that 

the applicable best available control measures will be utilized 

and/or installed during all periods of active operations; and 

(E) a description of the required contingency control measures (e.g., 

increased watering) for immediate implementation upon notice of 

visible dust crossing any property line. 

(2) In the event that there are special technical (e.g., non-economic) 

circumstances, including safety, which prevent the use of at least one of 

the control measures as identified by the Rule 403.1 Implementation 

Handbook for any of the sources identified in the fugitive dust control 

plan, a justification statement must be provided in lieu of the description. 

The justification statement must explain the reason(s) why the required 

control measures cannot be implemented. 

(3) Within 30 calendar days of the receipt of a fugitive dust control plan 

submitted pursuant to paragraph (e)(1), the Executive Officer will either 
Rule 403.1 (cont.) (Amended April 2, 2004) 

403.1 - 7 

approve or apply any necessary conditions to the fugitive dust control plan 

in writing. For a fugitive dust control plan to be approved, the 

requirements of paragraph (f)(1) must be satisfied. 

(4) The Executive Officer will apply conditions if the stated fugitive dust 

control plan measures do not satisfactorily conform to the best available 

control measures and guidance contained in the Rule 403.1 

Implementation Handbook. The conditions necessary to modify the 

fugitive dust control plan will be provided in writing to the person(s) 

identified in subparagraph (f)(1)(A). A letter to the Executive Officer 

stating that such modifications will be incorporated into the fugitive dust 

control plan shall be deemed sufficient to result in approval of the fugitive 

dust control plan. 

(5) Any fugitive dust control plan approved by the Executive Officer shall be 

valid for a period of one year from the date of approval. Any approved 

fugitive dust control plan must be resubmitted annually, at least 30 days 

prior to the expiration date, or the fugitive dust control plan shall expire as 

of the expiration date. If all fugitive dust sources and corresponding 

control measures or special circumstances remain identical to those 

identified in the previously approved fugitive dust control plan, the 

submittal may contain a simple statement of no-change (Form 403NC). 

Otherwise, a resubmittal must contain all the items specified in 

subparagraphs (f)(1)(A) through (f)(1)(E). 

(g) Wind Monitoring Implementation Requirements 

(1) The determination of wind speed conditions in excess of 25 miles per 

hour, as specified in paragraphs (d)(1) and (d)(5), shall be based on the 

following criteria: 

(A) For facilities with an on-site anemometer: 

(i) When the on-site anemometer registers at least two wind 

gusts in excess of 25 miles per hour within a consecutive 

30-minute period. Wind speeds shall be deemed to be 

below 25 miles per hour if there is no recurring wind gust 

in excess of 25 miles per hour within a consecutive 30-

minute period; or 

(B) For facilities without an on-site anemometer: 
Rule 403.1 (cont.) (Amended April 2, 2004) 

403.1 - 8 

(i) When wind speeds in excess of 25 miles per hour are 

forecast to occur in the Coachella Valley for that day. This 

condition shall apply to the full calendar day for which the 

forecast is valid. (The Executive Officer shall determine 

meteorological conditions which will cause wind speeds in 

excess of 25 miles per hour, and shall issue daily forecasts 

of expected wind conditions. Such forecasts shall be 

available to the public); or 

(ii) When wind speeds in excess of 25 miles per hour are not 

forecast to occur by the District, and fugitive dust 

emissions are visible for a distance of at least 100 feet from 

the origin of such emissions, and there is visible evidence 

of wind driven fugitive dust. 

(2) Any person who elects to install an on-site anemometer shall: 

(A) Notify the Executive Officer no more than 10 days after installing 

such equipment. The notification shall contain, at a minimum, the 

person's name, address, telephone number, description of the 

operation(s), and first day of operation, as specified in the District's 

Rule 403.1 Implementation Handbook. 

(B) Be subject to the provisions of subparagraph (g)(1)(B) for wind 

speed determinations if equipment outages, malfunctions, or 

invalid data exceed one hour during active operations on a 

calendar day. 

(h) Recordkeeping 

(1) A person subject to the provisions of this rule shall compile written daily 

records to document the specific actions taken to comply with this Rule. 

Such records shall be retained for not less than three years and shall be 

made available to the Executive Officer upon request. 

(2) In addition to the provisions of paragraph (h)(1), any person who elects to 

install an on-site anemometer shall also compile written records. Such 

records shall contain: 

(A) Location, vendor, model, and serial number of the anemometer; 

(B) The time of occurrence of any wind gust in excess of 25 miles per 

hour during hours of active operations; 
Rule 403.1 (cont.) (Amended April 2, 2004) 

403.1 - 9 

(C) The actions taken to comply with the provisions of paragraphs 

(d)(5) and (i)(3), as applicable. 

(i) Exemptions 

(1) The provisions of this rule shall not apply to ceased or inactive mining 

operations subject to the requirements of the Surface Mining and 

Recovery Act (SMARA) of 1975, provided that the provisions of the 

SMARA Reclamation Plan are implemented by the owner and are at least 

as stringent as those contained in this rule; 

(2) The provisions of paragraphs (d)(2), (d)(3), and (d)(4) shall not apply to: 

(A) Any active operation, open storage pile, or disturbed surface area 

for which necessary fugitive dust preventive or mitigative actions 

are in conflict with the Endangered Species Act as determined in 

writing by the State or federal agency responsible for making such 

determinations; 

(B) Any disturbed surface areas or bulk material deposits with a 

surface area less than 2,500 square feet; 

(C) Non-routine or emergency maintenance of flood control channels 

and water spreading basins. 

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

activities or soil mulching activities under the following conditions: 

(A) If the prohibitory requirements of this Rule have occurred 

during six or more hours of active operations on each of 

two previous consecutive days, then a one-day exemption 

will be allowed. (These activities would again be subject 

to the prohibitory requirements of this Rule following this 

one day exemption.) 

(B) If the prohibitory requirements of this Rule have occurred 

during sixty or more cumulative hours of active operations 

within a calendar month, then an exemption will be 

allowed for the remainder of the calendar month. (These 

activities would again be subject to the prohibitory 

requirements of this Rule at the start of the following 

month.) 

(C) During periods of precipitation. 
Rule 403.1 (cont.) (Amended April 2, 2004) 

403.1 - 10 

(4) The provisions of paragraph (e)(1) shall not apply to any active operation 

which is required to submit a dust control plan to any city or county 

government that has adopted a District-approved dust control ordinance. 

(j) Fees 

(1) Any person subject to a fugitive dust control plan submittal pursuant 

to paragraph (e)(1) shall be assessed applicable filing and evaluation 

fees pursuant to Rule 306. 

(2) The submittal of an annual statement of no-change, pursuant to 

paragraph (f)(5), shall not be considered as an annual review, and 

therefore shall not be subject to annual review fees, pursuant to Rule 

306.