Ministerial Resolution No. 5 of 17 May 1986 issuing the Regulation of the wastewater reuse and discharge

SULTANATE OF OMAN LAW ON THE CONSERVATION OF THE ENVIRONMENT AND PREVENTION OF POLLUTION MINISTERIAL DECISION 5/86 DATED 17TH MAY, 1986 REGULATIONS FOR WASTEWATER RE-USE AND DISCHARGE MINISTRY OF ENVIRONMENT AND WATER RESOURCES P.O. Box 323, MUSCAT TEL: 696444 REGULATIONS FOR WASTEWATER RE-USE AND DISCHARGE OBJECTIVE Article 1 In compliance with the Law on the Conservation ofthe Environment and Prevention of Pollution issued by Royal Decree 10/82 and its amendments, and in order to provide the greatest possible health and social welfare for the Nation and citizens and to protect the land and water resources, these Regulations concerning waste-water re-use and discharge have been effected. DEFINITIONS Article 2 The terms used in these Regulations shall be as defined in Royal Decree No. 10/82 and its amendments, with the following additions: 1. The Council Means the Council for Conservation of Environment and Water Resources. 2. The Ministry Means the Ministry of Environment and Water Resources. 3. The Law Means the Law on the Conservation of the Environment and Prevention of Pollution issued by Royal Decree No. 10/82 and its amendments. 4. Aquifer Means a porous, water bearing geological formation which consists of sand, gravel, sandstone and fractured or cavernous limestone, from which water can be drawn by wells in usable quantities for drinking, irrigation or other purpose. 5. Irrigation Means the use of wastewater for the watering of plants. 6. Treated Effluent Means the wastewater after treatment in a wastewater treatment plant. 1 7. Wastewater Means any polluted liquid discharged from any premises, trade or industrial or scientific premises. 8. Wastewater Treatment Plant Means a single unit or several different units or an integrated unit for treating wastewater, using physical or chemical or biological or other methods in an open or partially closed system. 9. Sludge Means a semi liquid waste with a solid concentration in excess of 2500 parts per million obtained from the treatment of wastewater. 10. Treated Sludge Means sludge which has been suitably conditioned for re-use or disposal in accordance with these Regulations. 11. User Means the person who uses the sludge produced from wastewater treatment plants by disposing of it to land owned or leased by him. 12. Contractor Means anyone transporting sludge for users or supplying it for reuse or disposal. 13. Utilisation of Treated Sludge means: a. Its application as a fertilizer. b. Its processing for fertilizer (dry sludge compost) ., etc. Article 3 The discharge to the environment of any wastewater or sludge in whatever form or condition is prohibited without a Permit from the Ministry or any other authorities approved by the Ministry. Article 4 Owners of current sources or areas of work which discharge wastewater or sludge to the environment must apply to the Ministry for a Permit to Discharge in a prescribed form within 4 months of the date upon which these Regulations come into force. 2 DISCHARGE AND RE-USE OF WASTEWATER Article 5 Wastewater must meet all the conditions shown in Table 1 which include the maximum limits permitted for its re-use. Article 6 The alternative methods for re-use of such wastewater shall be: (a) In a buried drip feed system for the irrigation of ornamental trees and shrubs in areas where there should not be public exposure. (b) In approved groundwater recharge system in areas where there should not be public exposure. These areas may include open land or wadis. (c) Re-use of treated effluent for industrial processes within a closed circuit system where there will not be any dangers to the workers. Full details of such re-use is to be submitted when making application for Permit to Discharge. (d) The re-use of treated effluent for flood, hosepipe, sprinkler or spray irrigation shall not be permitted without the prior consent of the Ministry. Article 7 The alternative methods for discharge of such wastewater shall be: (a) By controlled discharge to approved areas such as open land, wadis or water courses. (b) By discharge to sea conforming to the requirements of the Regulations con cerning the disposal of Liquid Effluents to the Marine Environment issued by the Council Decision No.7/84. (c) The discharge of wastewaters by deep well injection shall not be permitted. WASTEWATER QUALITY REQUIREMENTS Article 8 Wastewater quality requirements for re-use and discharge must be as given in Table 1. UTILISATION AND DISPOSAL OF SLUDGE Article 9 All sludge must be treated for disposal to the limits given in Table 2. 3 Article 10 Owners of wastewater treatment plants shall not deliver sludge to contractors or users unless the latter have obtained prior approval from the Ministry or other authorities approved by the Ministry for the proper disposal of such sludge. Article 11 Owners of wastewater treatment plants delivering sludge to contractors or users shall keep records specifying at least: (a) Date of Delivery. (b) Name and address of the Contractor or the User of Sludge. (c) The quantity delivered. Article 12 Sludge which is not being delivered to contractors or users shall either be utilised in a approved manner or be disposed of by the owners in an approved manner such as landfill or incineration. Monitoring Requirements Article 13 If wastewater, treated effluent or sludge being re-used or discharged are found to be outside the stated limits and represent a risk to public health then the Ministry or such authorities approved by the Ministry reserve the right to inspect, record and request samples and tests in accordance with Article 23 of the Royal Decree NO.1 0/82. Septic Tanks and Holding Tanks: Article 14 These Regulations shall not apply to the owners of septic tanks and holding tanks which shall be subjected to separate Regulations. Radioactive Material : Article 15 1 - The re-use of wastewater or sludge containing radio-active material shall not be permitted. 2 - The discharge of wastewater or sludge containing radio-active material shall in addition to these Regulations be subject to Regulations laid down by the International Atomic Energy Agency or such other Regulations that may be issued by the Ministry. PENALTIES Article 16 Any owner or person violating these Regulations will be punished by the Penalties stated in Section V of the Royal Decree No. 10/82. TABLE 1 - TABLE OF PARAMETERS FOR REUSE AND DISCHARGE OF WASTEWATER All Units are mg/ltr unless otherwise stated Parameter Limits (not greater than) Maximum Monthly average over any four consecutive weeks PHYSICAL Total Dissolved Solids 1500 1000 Total Suspended Solids 15 10 Turbidity (NTU.) 5 2 CHEMICAL . Aluminium 5 1 Ammoniacal Nitrogen (as N) 5 1 Arsenic 0.2 0.05 , Barium 2 1 Beryllium 0.3 0.1 Biochemicnl Oxygen Demand (5days) 15 10 Boron 2 1 Cadmium 0.03 0.01 Chemical Oxygen Oemand 100 50 Chloride 350 250 Chlorine, Free Residual (After 60 min. contact time) 0.5 (min) 0.5 (min) Chromium 0.5 0.1 Cobalt 0.5 0.1 Copper 0.3 0.2 Cyanide 0.1 0.05 Dissolved Oxygen 2.0(min) 2.0(min) Fluoride 2 1 Iron 5 1 Lead 0.5 0.1 Lithium 10 2.5 Magnesium 150 30 Manganese 1 0.2 Mercury 0.005 0.001 Molybdenum 0.05 0.01 Nickel 0.5 0.2 Oil and Grease 5 2 All Units are mg/ltr unless otherwise stated Parameter Limits (not greater than) Maximum Monthly average over any four consecutive weeks pH (pH units) 6-9 6-9 Phenols 1 0.1 Phosphorus (total as P) 30 20 Selenium 0.05 0.02 Sodium 200 70 Sulphate 400 200 Sulphide 0.1 0.05 Organic Nitrogen (Kjeldahl) 10 5 Total Nitrogen 50 30 Total Organic Carbon 50 20 Vanadium 1 0.1 Zinc 5 2 BACTERIOLOGICAL Total Coliforms 23 2.2 (MPN/100 ml) (Not to be (Determined over last 7 days exceeded in of completed analyses) any sample) Viable Pathogenic Ova and Cysts Nonedetectable None detectable Note: Only those parameters specified in the Permit to Discharge need to be analysed. TABLE 2 - LIMITS FOR DISPOSAL OF SLUDGE All units are grammes per ton of dry matter Parameter Limits (not greater than) Cadmium 30 Chromium 1000 Cobalt 100 Copper 1000 Lead 1000 Molybdenum 20 Nickel 200 Zinc 1000 6