Are there any standards for emergency ponds in chemical industry accidents?

This issue is too extreme: lol, when the wastewater is so polluted that it’s on fire, it’s no longer a matter of \"wastewater treatment\". Is this the way to play? Then you’re not playing for big prizes, right? :lol

It’s at least a bit less dangerous than other places.

1. The main standards or specifications to be followed for determining the volume of an accident tank include GB50483-2009, Q/SY 1190-2009, and Sinopec Safety and Environment Regulation No. 10, etc. The method for determining the volume of emergency accident ponds specified in GB50483 shall be applied to all projects involving wastewater from environmental risk incidents involving hazardous chemicals. When determining the amount of water required for fire fighting and the effective volume of cofferdams or fire dikes, the relevant provisions in codes such as the \"Code for Fire Protection Design of Buildings\" (GB50016-2006), the \"Code for Fire Protection Design of Petrochemical Enterprises\" (GB50160-2008), the \"Code for Design of Oil Depots\" (GB50074-2002), and the \"Code for Design of Fire Dikes in Tank Farm Areas\" (GB50351-2005) shall be followed ； The determination of the maximum rainfall is carried out in accordance with the \"Code for Design of Outdoor Drainage\" (GB50014-2006), the \"Code for Design of Water Supply and Drainage Systems in Petrochemical Enterprises\" (SH3015-2003), and other relevant standards. It is necessary to pay attention to distinguishing the scope of application of various standards and regulations, as well as the implementation of their specific provisions, based on factors such as the characteristics of the project, industry standards or codes, and the specific requirements determined by the capacity of the accident containment tank – especially in petrochemical enterprises and oil depots. 2. The capacity of the emergency accident pool should be determined comprehensively based on factors such as the capacity of the equipment where an accident occurs, the amount of water required for firefighting during an accident, and the amount of precipitation that may enter the emergency accident pool. The internal volume of the fire dike in the tank area, the volume of the drainage pipes leading to the accident pond below the highest liquid level of that pond under gravity-fed conditions, and the volume of the existing facilities for storing accident wastewater can all be considered as effective volumes for storing accident wastewater. When calculating the wastewater volume from emergency accidents, accidents in the plant area or tank area are not considered to occur simultaneously; the maximum value among them is taken. The drainage capacity of the accident wastewater collection system should be verified based on the maximum flow rate of accident wastewater, and measures for fire protection, explosion prevention, leakage prevention, corrosion resistance, freezing protection, flood control, buoyancy resistance, and seismic resistance of the drainage system must be specified. 3. It is necessary to pay attention to the amount of rainwater that enters the accident tank in the event of an accident, and to distinguish clearly between this and the amount of rainwater that occurs at the beginning of normal production (i.e., initial rainwater); the two should not be confused. Firstly, the duration of rainfall varies. In normal production and operation, initial rainfall refers to the rain that has just fallen, namely the maximum precipitation amount during the first 10–20 minutes of a rainfall event. The calculation of design parameters must be carried out using the storm intensity formula for short-duration rainfall as specified in GB50014 ； The precipitation amount at the time of the accident should be determined based on the fire fighting duration of the accident (generally 2–6 hours according to GB50016 and GB50160, and 6–10 hours according to Q/SY 1190). Secondly, the catchment areas differ; the catchment area for initial rainfall must take into account the total catchment area of both the production area and the storage area ； During an accident, only the maximum rainfall that can enter the accident drainage system from the plant area or tank farm alone is taken into consideration; simultaneous water accumulation is not considered. Moreover, measures should be taken to minimize the area from which rainwater enters the accident drainage collection system. 4. When the accident tank needs to be used under normal conditions (for example, when shared with pre-event rainwater tanks), the occupied volume shall not exceed 1/3 of the accident tank’s capacity, and technical measures must be in place to allow for emergency emptying in the event of an accident. The wastewater treatment accident tank cannot be used as an accident storage facility; it is not permissible to transfer risks further onto the wastewater treatment system. 5. The determination of the volume of the accident tank should be carried out in conjunction with the project’s three-level prevention and control system (pollution source control, process treatment, and final discharge), adhering to the principle of \"prevention first, combined prevention and control\" in order to keep wastewater in an accident scenario within the plant and prevent it from being released into the environment, thus ensuring environmental safety. The primary prevention and control system must include the construction of cofferdams around the plant area, fire dikes in the tank areas, as well as related facilities such as spare tanks, liquid storage tanks, oil separation tanks, diversion systems, and facilities for switching between clean and wastewater – all of these are needed to prevent environmental contamination caused by polluted rainwater or leaks resulting from minor accidents ； The secondary prevention and control system must include emergency accident ponds, sedimentation dams, and related facilities (such as accident drainage systems) to prevent environmental pollution caused by leaks of materials from individual production units (tank areas) or by fire-fighting wastewater ； The three-level prevention and control system must include end-point accident buffer facilities and related supporting systems, in order to prevent environmental pollution caused by the leakage of materials from two or more production units (tank farms) or by firefighting wastewater.

Emergency ponds for chemical accidents must be designed in accordance with specific standards. Since these emergency ponds are relatively simple in structure yet pose certain risks, chemical industry regulations provide detailed guidelines regarding them. Tank areas, liquid storage ponds, oil separation tanks, diversion facilities, and sewage systems within plant areas, as well as wastewater from equipment maintenance and rainwater, all need to be directed into these emergency ponds. When the water level in these ponds reaches a certain threshold, it is necessary to contact the environmental protection authorities so that specialized waste removal vehicles can transport the waste to locations designated by the authorities for proper treatment, thereby preventing pollution caused by rainwater or leaks resulting from minor accidents；