In EPA’s RMP standard there are four (4) TOXIC substances which have listed concentrations:
- Hydrochloric acid 37% or greater
- Hydrofluoric acid 50% or greater
- Nitric acid 80% or greater
- Ammonia 20% or greater
If we have any of these four (4) substances in solution AND their concentration is LESS THAN (<) the listed concentration, we do NOT need to consider the solution(s) at all.
However, if we have any of these four (4) substances in solution AT or ABOVE their listed concentration, we MUST DETERMINE THE WEIGHT OF THE SUBSTANCE IN THE SOLUTION and use that weight to calculate the quantity present. If that quantity is GREATER THAN the RMP threshold quantity (TQ), the process is an RMP covered process.
For example, the University that recently got cited for not having an RMP for their power and heat plant’s SCR used aqueous ammonia in concentration over 20% and the process exceed the 20,000 pounds TQ.
If the solution is 25% ammonia, the process would need 80,000 pounds of the entire solution to meet the threshold quantity; if the solution is 44% ammonia, the process would need just 45,455 pounds to meet the threshold quantity.
Here is the formula we use to establish our process quantity of the EHS… Quantity of Solution (gallons) X % of regulated substance = Quantity of regulated substance
For the power plant to have an RMP covered process using 29% aqua ammonia they would have needed to have 70,000 gallons or more of 29% aqua ammonia to exceed the 20,000 pound TQ.
70,000 gallons X 29% = 20,300 pounds of ammonia