Effluent discharge limits in Morocco
Morocco uses a general industrial-discharge table for wastewater without a sector-specific limit, alongside separate sector standards for particular industries. That distinction is decisive: a paper mill, refinery, sugar plant, cement works or surface-treatment operation may be governed by a specific table rather than the general figures shown first.
For discharge into surface or groundwater where no specific sector standard applies, Morocco’s general limits include pH 5.5–9.5, temperature 30 °C, suspended solids 100 mg/L, BOD₅ 100 mg/L, COD 500 mg/L, Kjeldahl nitrogen 40 mg/L, total phosphorus 15 mg/L, oil and grease 30 mg/L and hydrocarbons by infrared 15 mg/L.
Those are the general values under Joint Order No. 2942-13 as amended by Order No. 3286-17, effective from 1 January 2018. They do not override sector-specific values or the discharge authorisation issued by the relevant Basin Agency.
First question: general or sector-specific limit?
The governing framework is the 2005 decree on discharges, flows, releases and deposits into surface or groundwater. It provides for discharge authorisation and for general or specific limit values. The current general table applies only when an activity does not have specific limits.
| Facility or route | Likely basis | Action before design |
|---|---|---|
| Industry with no published sector table | General values, amended in 2017 | Use the table below and seek authorisation from the relevant Agence de Bassin Hydraulique. |
| Pulp, paper and board | Specific industry limit values | Use the paper-sector table, not the general COD/BOD figures. |
| Sugar, cement, petroleum refining, hot-dip galvanising and some other named activities | Specific industry limit values | Identify the exact activity and official sector order; values can differ dramatically. |
| Urban/domestic wastewater discharge | Domestic-specific values | Not the industrial general table. The domestic values are a separate instrument. |
| Discharge to a sewer | Network/operator conditions plus applicable regulation | Obtain the receiving operator’s written trade-effluent conditions. |
General limit values for discharge to surface or groundwater
| Parameter | General limit | Relevance to a flotation plant |
|---|---|---|
| Temperature | 30 °C | Equalise or cool hot process and cleaning streams. |
| pH | 5.5–9.5 | Design pH correction after coagulant dosing. |
| Suspended solids (MES) | 100 mg/L | Well within the range of DAF with stable coagulation. |
| BODâ‚… | 100 mg Oâ‚‚/L | DAF removes particulate BOD; soluble load requires biological treatment. |
| COD (DCO) | 500 mg Oâ‚‚/L | A relatively high general limit, but wastewater composition still determines the required process. |
| Kjeldahl nitrogen | 40 mg N/L | DAF does not nitrify ammonia; assess the biological stage. |
| Total phosphorus | 15 mg P/L | Often achievable using iron-based coagulation at DAF. |
| Oil and grease | 30 mg/L | Core DAF duty for food, edible-oil and industrial wash water. |
| Hydrocarbons by infrared | 15 mg/L | Free oil separation plus DAF is usually the correct front end. |
| Detergents, total | 3 mg/L | Source control matters; surfactants can prevent bubble/floc attachment. |
| Electrical conductivity | 2,700 µS/cm | DAF does not remove dissolved salts; check source water and reagent contribution. |
| Sulphates | 600 mg/L | Iron sulphate and alum add sulphate; calculate at design dose. |
| Free sulphides | 1 mg/L | Iron dosing can help precipitate sulphide, but control Hâ‚‚S safety risk upstream. |
| Free cyanide | 0.5 mg/L | Requires dedicated treatment and strict segregation. |
| Phenol index | 0.5 mg/L | Not a flotation-only problem. |
| Cadmium / mercury / lead | 0.25 / 0.05 / 1.0 mg/L | Metals precipitation with robust final solids capture. |
| Total copper | 2 mg/L | Control soluble-metal pH and complexation before sizing a clarifier/DAF. |
| Salmonella / cholera vibrios | Absent in 5,000 mL | Disinfection is a separate stage where required. |
Sampling and the 95% compliance rule
The amended general regime is more than a list of concentrations. Compliance is assessed from at least four composite samples per year, taken during the activity period. At least 95% of the parameter averages must meet the limit; the remaining averages may not exceed the general limit by more than 25%, except for pH and temperature. This makes a well-controlled, representative sampling point essential.
For an industrial DAF, install a final-sample point after all treatment and avoid a design that only passes a grab sample on a calm day. Equalisation, automated dose control and a stable sludge-removal programme are what turn a good jar test into repeatable compliance.
Authorisation and industrial responsibilities
A discharge into surface or groundwater requires authorisation under the water framework. The relevant Agence de Bassin Hydraulique is the practical starting point for the discharge file and receiving-water conditions. An industrial operator should establish the destination, flow and contaminant profile; identify any specific sector table; provide its treatment design and monitoring proposal; and obtain written conditions before commissioning. A municipal sewer connection remains a separate discussion with the receiving operator.
What this means for DAF design in Morocco
- DAF is a strong fit for the 30 mg/L oil and grease target. It also gives margin on suspended solids and, with iron coagulant, the 15 mg/L phosphorus target.
- COD 500 mg/L is not a universal goal. Where a named industrial sector has its own value, that specific value takes precedence. Build the process train around the right table.
- Check conductivity before selecting chemicals. Coagulation can improve solids separation but cannot remove the dissolved salts that create a 2,700 µS/cm compliance issue.
- Use direct-discharge figures only for the actual discharge route. A sewer-admission agreement can have different limits and sampling arrangements.
- Design for composite-sample compliance. Equalisation and automatic coagulant/polymer control are often more valuable than chasing a one-time peak removal result.
Source and verification
| Framework decree | Decree No. 2-04-553 of 24 January 2005 on discharges, flows, releases and deposits into surface or groundwater |
| General values | Joint Order No. 2942-13 of 7 October 2013, amended by Joint Order No. 3286-17 of 4 September 2017 |
| Effective date for amended general values | 1 January 2018 |
| Competent authority | Relevant Agence de Bassin Hydraulique, with sector and local authorities as applicable |
| Sources | FAOLEX legal profile — Morocco · ONEE environmental assessment citing the amended general regime |
| Checked | 7 August 2026 |
Frequently asked questions
What is the general COD limit for industrial discharge in Morocco?
500 mg Oâ‚‚/L under the general table for discharges to surface or groundwater where no specific sector standard applies. The same table sets BODâ‚… 100 mg/L and suspended solids 100 mg/L. A named sector can have a different, specific table.
What is the oil and grease limit in Morocco?
The general limit is 30 mg/L for oils and fats, and 15 mg/L for hydrocarbons measured by infrared. DAF is normally the correct separation step for these parameters.
Can a DAF meet the Moroccan general limits on its own?
It can usually meet the oil, grease and solids targets and can precipitate phosphorus with iron dosing. It will not reliably remove dissolved COD or ammonia; a biological stage is needed when those drive compliance.
How is compliance sampled under Morocco’s general limit regime?
The amended general regime uses at least four composite samples per year during the activity period. At least 95% of parameter averages must comply, with restricted allowance for the remainder; pH and temperature are exceptions. Confirm the exact monitoring condition in your authorisation.