What does NCEC's Riyadh dust guide require on a construction site?

Short answer

The guide applies to all government and private construction in the Riyadh Metropolitan area and requires a Dust Management Plan (DMP) within the CEMP, submitted at least 30 calendar days before mobilisation, with no dust-generating work before written approval. Above 25 km/h of wind, excavation, grading, trenching, demolition, crushing, stockpile handling and waste loading must stop. Real-time PM10 monitors are required on medium and high-risk sites, and the guide records a violation when 1-minute PM10 data exceed 340 µg/m³ for more than 2 minutes. Several figures differ between sections of the guide or from the Air Quality regulation.

Key terms used in this guide 5 terms

Environmentally sensitive areas: Areas with environmental significance whose degradation has negative repercussions for the environment. They include protected areas, parks, forests, wetlands, significant bird habitat, mangroves, landscaped sites, watersheds, water catchment and run-off areas, beaches, waterways, aquifers or any other area identified or declared as environmentally sensitive by the State, the Ministry or the national environmental centers. Arabic: المناطق الحساسة بيئياً (meaning “areas sensitive environmentally”) Permits reg. Art. 1
Point source: Permanent or semi-permanent activities resulting in the emission of air pollutants, such as industrial stacks, energy production plants, and the dust resulting from mining activities and construction works, amongst others. Arabic: المصادر الثابتة (meaning “the fixed (stationary) sources”) Air reg. Art. 1
Sensitive receptors: Receptors that are likely to be severely affected by activity or project due to their geographical proximity or sensitive nature. They include environmental elements, living species, archeological, cultural and religious sites, and community groups (such as endangered species, hospitals, elder care centers, schools, residential complexes, and others). Arabic: المستقبلات الحساسة (meaning “the sensitive receivers”) Permits reg. Art. 1
Treated wastewater: Wastewater emerging from a treatment plant or a treatment process, which was treated to reduce the adverse environmental impact in compliance with specific environmental standards and requirements. Arabic: مياه الصرف المعالجة (meaning “treated drainage water”) Aqueous reg. Art. 1
Wastewater: Water whose use has changed its color, taste, odor, or level of health or environmental security. This includes water used for health, industrial or agricultural purposes, including cooling water and water from desalination plants (brine). Arabic: مياه الصرف (meaning “drainage water”) Aqueous reg. Art. 1

All 49 terms in the NCEC glossary

On this page

Who does the guide apply to?
What must the Dust Management Plan contain, and when is it due?
When must work stop for wind?
What real-time monitoring is required?
What site controls does the guide prescribe?
Where is the guide inconsistent?
What can go wrong?

Who does the guide apply to?

The guide applies to all government and private construction and mega-development projects in the Riyadh Metropolitan area. It covers all contractors, subcontractors and project managers responsible for site operations.^{Dust guide, section 1.3}

It focuses on fugitive dust, with primary emphasis on PM10. Gases, noise and vibration are left to other regulatory instruments.^{Dust guide, section 1.3}

The guide describes itself as a clear, practical and enforceable framework.^{Dust guide, section 1.2}

It contains no penalty table of its own. It refers the allowable PM10 threshold to the Air Quality Regulations and lists NCEC field visits, warnings, fines and stop-work orders as enforcement tools.^{Dust guide, section 3.11}

Projects are classed into three risk categories:

Category I, low risk	Site area under 2,000 m²
Category II, medium risk	Site area 2,000 to 5,000 m²
Category III, high risk	Site area over 5,000 m², or more than 50 truck movements a day, or on-site crushers or batching plants

Table source^{Dust guide, Table 1}

What must the Dust Management Plan contain, and when is it due?

Before construction, each project must carry out a baseline assessment of soil dustiness, climate and winds, and sensitive land uses within at least 1 km, documented in the DMP.^{Dust guide, section 2.1}

Medium and high-risk projects must also provide sensitivity mapping (GIS or equivalent) that overlays receptors with wind exposure.^{Dust guide, section 2.1}

Every project must prepare a DMP within the CEMP. The DMP must:^{Dust guide, section 4.2}

State the risk classification and project context.^{Dust guide, section 4.2}
Identify dust sources and specify mitigation measures, prioritising water-efficient options.^{Dust guide, section 4.2}
Describe monitoring systems (PM10 stations, anemometers, cameras) consistent with Annex B.^{Dust guide, section 4.2}
Allocate roles and responsibilities, including the Dust Control Coordinator and deputies.^{Dust guide, section 4.2}
Integrate the Annex A wind protocol with stop, resume and restart procedures.^{Dust guide, section 4.2}
Cover complaints handling, training and reporting using the Annex D forms.^{Dust guide, section 4.2}
Include an Equivalency Section where alternatives to prescribed measures are proposed.^{Dust guide, section 4.2}

The timing rules are:

Submit the DMP at least 30 calendar days before mobilisation. No dust-generating activity may start before written approval.^{Dust guide, section 4.2}
Revise the DMP within 10 working days of a material change in scope, contractors, controls or monitoring layout.^{Dust guide, section 4.2}
Run at least 2 weeks of baseline PM10 and wind monitoring at the site boundary before clearance.^{Dust guide, section 4.3}
Keep the approved DMP on site and produce it to inspectors on request.^{Dust guide, section 4.2}

The CEMP must name a Dust Control Coordinator responsible for implementation across all contractors.^{Dust guide, section 4.6}

At demobilisation, stockpiles must be removed or stabilised, exposed areas covered, roads cleaned and a Dust Close-Out Report submitted. A final inspection or regulator approval is required before site handover.^{Dust guide, section 4.7}

When must work stop for wind?

Annex A sets three wind bands:

Below 15 km/h	Routine operations and controls
15 to 25 km/h	Enhanced suppression, demolition suspended
Above 25 km/h	Excavation, grading, trenching, demolition, crushing, stockpile handling and waste loading suspended

In the 15 to 25 km/h band, enhanced suppression includes:^{Dust guide, Annex A}

Hourly watering or suppressants on earthworks and roads.^{Dust guide, Annex A}
Stockpiles fully covered or misted, with drop heights of 1 m or less.^{Dust guide, Annex A}
Paved roads swept twice per shift and wheel-washes inspected hourly.^{Dust guide, Annex A}
Fogging and spray cannons at crushers.^{Dust guide, Annex A}

Above 25 km/h only enclosed operations may continue, such as silos and enclosed batching plants with PM10 filters of at least 99 percent. Covers and stabilisers must be inspected before work resumes.^{Dust guide, Annex A}

Site managers are responsible for halting works above the thresholds. Daily logs must record wind, dust and mitigation actions.^{Dust guide, Annex A}

Section 3.7 separately requires demolition to be suspended when wind exceeds 15 km/h and limits active demolition to 100 m² at a time.^{Dust guide, section 3.7}

Table source^{Dust guide, Annex A}

What real-time monitoring is required?

Section 3.11 requires continuous real-time PM10 monitoring with live data sent by GSM to the RCRC and NCEC unified dashboard. It calls for 1 or more stations on medium-risk sites and 2 or more on large or mega sites.^{Dust guide, section 3.11}

Monitors must be sited, installed, tested and linked to the dashboard before construction starts. Cameras are required at all entry and exit points with at least 90 days of storage, and anemometers must be 2 to 3 m above ground.^{Dust guide, section 3.11}

Annex B sets minimum monitor specifications:

Optical light-scattering PM10 measurement with a correlation of R² 0.85 or better against a reference method.^{Dust guide, Annex B}
Logging every minute or less, at least 6 months of storage and automatic GSM or 4G upload.^{Dust guide, Annex B}
Rated for at least 50 °C and IP65 or higher.^{Dust guide, Annex B}
Weekly zero or bump checks, quarterly field calibration and an annual regulator co-location audit.^{Dust guide, Annex B}
At least 12 hours of battery backup, at least 90 percent daily data completeness and at least 2 years of data retention.^{Dust guide, Annex B}

Under Annex B, a 1-minute PM10 reading of 250 µg/m³ triggers a warning to the contractor. Exceeding 340 µg/m³ for more than 2 minutes is recorded as a violation and dust-generating work must stop, and if the exceedance continues for 30 minutes the Annex A suspension protocol applies.^{Dust guide, Annex B}

Violations apply for each incident over the threshold. The contractor must send NCEC an incident report on the cause of each exceedance.^{Dust guide, section 3.11}

Small low-risk urban projects must apply all the dust measures but need not install fixed PM10 stations or cameras unless the regulator directs it because of nearby sensitive receptors.^{Dust guide, section 3.12}

What site controls does the guide prescribe?

Key controls for earthworks, roads, exits and stockpiles include:

A stabilised roadway for all vehicle movement before earthworks, inactive areas stabilised if idle more than 5 days, and bucket drop heights of 1.5 m or less (1 m in high wind).^{Dust guide, section 3.1}
Daily watering or suppressants on unpaved roads, speed limits of 10 km/h unpaved and 20 km/h paved, tarps overlapping truck sides by at least 30 cm, and spillage cleaned within 15 minutes.^{Dust guide, section 3.2}
Closed-loop wheel-wash (at least 20 seconds per axle) or submerged rumble racks (at least 8 m) at exits, with no visible trackout beyond 15 m from the gate.^{Dust guide, section 3.3}
Stockpiles centralised, sprayed immediately, shaped to 3 m or less and kept at least 200 m from schools, hospitals and mosques.^{Dust guide, section 3.5}
Cement in sealed silos with PM10 filters of at least 99 percent, and no dry sweeping or compressed-air cleaning.^{Dust guide, sections 3.5 and 3.6}
Wet stone cutting only, with outdoor dry cutting prohibited.^{Dust guide, section 3.9}

Crushers may be used only on Category III projects with a critical schedule. They must be fully enclosed where possible, with fogging sprays and spray cannons.^{Dust guide, section 3.8}

Dust suppression must not rely on potable water unless no alternative exists. Licensed shallow groundwater, treated wastewater, desalination reject or other industrial-grade water should be prioritised.^{Dust guide, section 5.1}

If misting systems, sprays or cannons fail, dust-generating work must stop until controls are restored. A backup water source must always be available.^{Dust guide, section 5.2}

Small projects are limited to 1 m stockpiles, must remove covered skips daily, and may not place excavation, demolition or construction waste outside the project boundary.^{Dust guide, section 3.12}

Where is the guide inconsistent?

Several provisions differ between sections of the guide or from the Air Quality regulation, and the guide does not say which value prevails. The figures that differ are:

Annex B applies 340 µg/m³ to 1-minute PM10 data, while section 3.11 says the allowable threshold follows the Air Quality Regulations.^{Dust guide, Annex B}
In the Air Quality regulation, 340 µg/m³ is a 24-hour average with 12 allowed exceedances a year, and there is no 250 µg/m³ warning level.^{Air reg. Appendix 1}
Section 3.11 asks for 2-minute live logging, while Annex B requires a logging interval of 1 minute or less.^{Dust guide, section 3.11}
Idle surfaces must be stabilised after more than 5 days in section 3.1, but after more than 7 days in section 3.4.^{Dust guide, sections 3.1 and 3.4}
Section 3.8 first places crushers 200 m from sensitive and residential areas, then bans crushers within 500 m of any sensitive area.^{Dust guide, section 3.8}
Section 3.2 requires sweeping of adjacent public roads once every hour for medium and large projects, then at least once per day.^{Dust guide, section 3.2}
Wind fences are placed at 15 times the pile height in section 3.4, but downwind at 10 to 15 times the fence height in section 3.5.^{Dust guide, sections 3.4 and 3.5}

Other inconsistencies concern scope, approvals and references:

Section 3.12 describes small projects as 'less than 1 hectare (2.0000m²)', while Table 1 defines low risk as under 2,000 m².^{Dust guide, section 3.12}
Section 3.11 ties station numbers to risk class, while Annex B ties them to area (at least 1 station for sites of 5 ha or less). A 4 ha site is Category III under Table 1 but a small site under Annex B.^{Dust guide, Annex B}
The English text of section 4.2 sends the DMP to 'the Authority' without naming it, while the Arabic text names NCEC and asks for the plan at least 30 days before site preparation. Annex B says RCRC approves the monitoring layout, and section 3.11 refers to approval by NCEC and RCRC.^{Dust guide, section 4.2}
Section 4.2 refers to Annexes C-1, C-2, C-3 and H and to Part VII, and section 4.4 to Article 5. None of these appear in the published guide.^{Dust guide, sections 4.2 and 4.4}
The Air Quality regulation requires point source operators to keep operating, test and maintenance records for at least 5 years, longer than the 2-year data retention in Annex B.^{Air reg. Art. 5, Fifth (1)(a)}

Record your choice in the DMP

Where the guide gives two values, state in the DMP which one the site applies and why. Choosing the stricter value leaves less room for dispute at inspection.

What can go wrong?

These are the points where Riyadh projects most often run into trouble under the guide:

What can go wrong

Mobilising before written DMP approval. The guide bars dust-generating work until approval and asks for submission at least 30 calendar days ahead.^{Dust guide, section 4.2}
Forgetting the baseline. At least 2 weeks of PM10 and wind monitoring must be completed before clearance, so it must be programmed before earthworks.^{Dust guide, section 4.3}
Slipping into Category III without noticing, through more than 50 truck movements a day or by bringing a crusher or batching plant onto site.^{Dust guide, Table 1}
Treating PM10 spikes as minor. Each incident over the threshold is a separate violation and needs an incident report to NCEC.^{Dust guide, section 3.11}
Having no backup water or spare pump. A suppression failure means dust-generating work must stop immediately.^{Dust guide, section 5.2}
Monitors that stop transmitting or fall below 90 percent daily data completeness.^{Dust guide, Annex B}
Site handover held up by a missing Dust Close-Out Report or final inspection.^{Dust guide, section 4.7}

Preparing a Dust Management Plan for a Riyadh project?

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References

Each small number in this guide shows the article or section that point comes from. Hover over or tap a number to see it, or open the full list below.

Show all 27 references and the 3 regulation texts

Dust guide, section 1.3
Dust guide, section 1.2
Dust guide, section 3.11
Dust guide, Table 1
Dust guide, section 2.1
Dust guide, section 4.2
Dust guide, section 4.3
Dust guide, section 4.6
Dust guide, section 4.7
Dust guide, Annex A
Dust guide, section 3.7
Dust guide, Annex B
Dust guide, section 3.12
Dust guide, section 3.1
Dust guide, section 3.2
Dust guide, section 3.3
Dust guide, section 3.5
Dust guide, sections 3.5 and 3.6
Dust guide, section 3.9
Dust guide, section 3.8
Dust guide, section 5.1
Dust guide, section 5.2
Air reg. Appendix 1
Dust guide, sections 3.1 and 3.4
Dust guide, sections 3.4 and 3.5
Dust guide, sections 4.2 and 4.4
Air reg. Art. 5, Fifth (1)(a)

How to read these references 2 texts cited

Dust guide: NCEC guideline: Mitigating Fugitive Dust Emissions from Construction Activities in Riyadh
Air reg.: Executive Regulation for Air Quality

Art. 7(4)(b) means Article 7, paragraph 4, item (b).
First, Second and Third are the numbered parts some articles are divided into. The Arabic texts write them أولاً، ثانياً، ثالثاً (meaning first, second, third).

Every text we cite is listed on our regulations page.

Regulation texts this guide is written from

NCEC guideline: Mitigating Fugitive Dust Emissions from Construction Activities in Riyadh (Dust control and containment measures for construction work in Riyadh)
Executive Regulation for Air Quality (Environmental Law, Royal Decree M/165)
Regulation of Safety Procedures for Excavations in Water and Sanitation Projects

This guide is general information written from the regulation texts listed above. It is not legal advice. Regulations change, and the official text always prevails. Spotted something out of date? Request a change.