--- title: "SCAQMD 1466 Limits: PM10 | Aethair" description: "SCAQMD Rule 1466 PM10 dust threshold for earth-moving on contaminated soil: the 25 µg/m³ upwind/downwind limit, monitor rules, and a recommended setup." url: https://aethair.io/standards/scaqmd_1466/ --- Compliance · South Coast Air Quality Management District # SCAQMD Rule 1466: particulate emissions from soils with toxic air contaminants Ambient air: earth-moving on contaminated soil (South Coast AQMD, California) South Coast Air Quality Management District Rule 1466 (amended June 4, 2021) controls dust from earth-moving on sites whose soil contains toxic air contaminants. It requires **continuous, direct-reading PM10 monitoring upwind and downwind** of the work. When the **downwind minus upwind PM10 concentration exceeds 25 µg/m³ as a 120-minute rolling average**, earth-moving must stop or dust controls must be applied **until the level is at or below 25 µg/m³ averaged over 30 minutes**. [Schedule a call](https://calendly.com/d/ctdd-mkr-v9v/aethair-demo-website) [Configure SCAQMD 1466 Monitoring](https://aethair.io/build/?params=pm10\&setting=outdoor) At a glance **South Coast Air Quality Management District** Ambient air: earth-moving on contaminated soil (South Coast AQMD, California) 1 parameter · 1 limit value [PM10](https://aethair.io/parameters/pm10/) 1 device measures them all - **Aethair PRO** [Official text from South Coast Air Quality Management District](https://www.aqmd.gov/docs/default-source/rule-book/reg-xiv/rule-1466.pdf) The standard ## What Rule 1466 Is The monitors must either follow an EPA-approved equivalent method for PM10 or be approved under Rule 1466. Upwind and downwind monitors must be identical in make, model, and settings and log data at least every minute, with the precision and zero checks the rule sets out. Limit values ## SCAQMD 1466 Limit Values Every value South Coast Air Quality Management District publishes for the parameter below, with its averaging period, as the standard states it. [**PM10** Particulate Matter](https://aethair.io/parameters/pm10/) **25 µg/m³** *120-minute rolling, downwind minus upwind* earth-moving stops or dust controls apply until at or below 25 µg/m³ averaged over 30 minutes Who it applies to ## Who It Applies to Owners and operators moving soil that contains toxic air contaminants of concern at a site in the South Coast district designated by the U.S. EPA as a Superfund National Priorities List site, by the California Department of Toxic Substances Control as a Brownfield or Cleanup Program site, by a state or regional water board as a Site Cleanup Program site, or by a regulatory agency as a Hazardous Material Release site. It does not apply to less than 50 cubic yards of soil or to soil removed for sampling. Wind conditions matter too: earth-moving must cease when wind speed exceeds the limit set in the rule. Monitoring ## How Monitoring Demonstrates Compliance Compliance is the paired upwind/downwind PM10 record at one-minute resolution, the rolling 120-minute differences against 25 µg/m³, and the documentation of every stop or control measure. The rule adjusts the comparison when the wind shifts more than 90 degrees from the prevailing direction, so wind direction has to be recorded with the dust readings. [Customize this configuration](https://aethair.io/build/?params=pm10\&setting=outdoor) ### Who measures each parameter | Parameter | Aethair PRO | Aethair IAQ | External | | - | - | - | - | | [PM10](https://aethair.io/parameters/pm10/) | Built in | Built in | [3 instruments](https://aethair.io/parameters/pm10/) via Thiamis | Devices ## Devices That Cover SCAQMD 1466 How much of this standard one Aethair monitor covers, followed by the third-party instruments in the sensor catalog that measure its parameters. Each connects to Environet through a Thiamis gateway, which adds whatever the monitor leaves out. Aethair monitors [**Aethair PRO** Built-in sensors Covers it](https://aethair.io/products/pro/) Covers it on its own [**TSI DustTrak** Particulate & Dust Monitors](https://aethair.io/sensors/tsi-particulate-dust-monitors/) [**Met One E-BAM** Particulate & Dust Monitors](https://aethair.io/sensors/met-one-particulate-dust-monitors/) [**Trolex** Particulate & Dust Monitors](https://aethair.io/sensors/trolex-particulate-dust-monitors/) Solutions ## Solutions Judged Against SCAQMD 1466 ### [Perimeter Monitoring](https://aethair.io/solutions/perimeter-monitoring/) Site boundary dust, silica, and noise compliance [All solutions](https://aethair.io/solutions/) Article Library ## Articles on SCAQMD 1466 ### [Fenceline Air Quality Monitoring: Equipment and Approaches](https://aethair.io/resources/fenceline-air-quality-monitoring/) Compare fenceline air quality monitoring approaches: standalone stations, pelican-case kits, and connected 4G sensor networks. [All articles](https://aethair.io/resources/) Questions ## SCAQMD 1466 FAQ What is the Rule 1466 PM10 threshold? 25 µg/m³, calculated as the downwind minus the upwind PM10 concentration over a 120-minute rolling average. Above it, earth-moving stops or dust controls apply until the level is at or below 25 µg/m³ averaged over 30 minutes. What monitors does Rule 1466 require? Continuous direct-reading PM10 monitors upwind and downwind, following an EPA-approved equivalent method or approved under the rule, identical in make, model, and settings, logging at least every minute. Does wind matter under Rule 1466? Yes. The rule adjusts the upwind/downwind comparison when the wind shifts more than 90 degrees from the prevailing direction, and earth-moving must cease above the wind speed it sets.