Dyke Wall Construction: What Safety Parameters Should We Consider for Different Materials?

Dyke Wall Construction Parameters

The question from my Safety Officer is: What parameters should be considered for Dyke wall construction, and are there standard guidelines for Dyke walls regarding:

1. Materials other than petroleum (acid, alkali, toxic, etc.)
2. Petroleum materials

Regards,
Abhay

[QUOTE=dipil;1377737] Dear Abhay, Just go through the link provided below: CR4 - Thread: Dyke Wall Dimension for Storage of Chemical Hope this will help you somehow. Regards, dipil

Hi Abhay, I previously used that link but did not find enough information.

Regards, Abhay

Dipil asked me to help you with this chemical question.

The two questions around dyke operations are simple.

The first question is: are you keeping out contaminants or trying to contain chemicals from spilling or leaching out?

The next question is: is it inside risks or outside storage risks?

After that, the risk factors are simple to understand.

The first thing to consider is the type of chemical you are protecting.

The second factor is the risk during construction, like heavy traffic in the area, which can lead to spillage, leakage, or damage to the dyke. For example, similar to the fire rating on a steel door, how long before the chemical breaks down the dyke or if equipment is used around it, the shock impact to the dyke strength if someone hits it.

The standard height is 36 inches off the ground with a minimum of reinforced steel-inlaid cement about 6-8 inches thick. Additionally, the containment of chemicals and inner contaminants must be collected inside the dyke area.

If you answer these questions, the rest of the process will be straightforward.

For petrochemicals, a 30-degree built-up berm is laid on the outside area as an additional protective barrier, with grounding rods placed outside the wall area leading to the tanks to prevent electrical discharge.

The inner floor is also reinforced with a six-inch base, and the entire area has a built-in protective liner specific to the chemical to prevent leaching of the product.

Regarding the dyke wall, whether it should contain petroleum materials or chemicals, the size of the dyke wall should be 1.25 times the total capacity of the storage tanks. The type of flooring will vary according to the materials used.

Regards,
T.S. SRINIVASAN

Hi Abhay,

Please find some input from my side on the same:

1. Secondary containment for a single container (tank) should be 110% of the primary container.

2. Secondary containment for multiple containers should be 150% of the largest container's volume OR 10% of the aggregate volumes of all containers, whichever is greater.

3. All secondary containment systems open to rainfall must be able to hold 4.5 inches of rainfall in addition to the required secondary containment volume.

4. All secondary containment systems open to fire sprinkler discharge must be able to hold the discharge from all sprinkler heads over the secondary containment system for 20 minutes in addition to the required secondary containment volume.

5. The dyke for the storage tanks should have a minimum height of 30 cm.

6. The dyke and dyked area should be lined with a material that is chemically resistant and compatible with the material being stored.

7. Uncontrolled drainage from a secondary containment system is not allowed. Accumulated rainwater or sprinkler flow water may only be released from a secondary containment system after it has been determined to be uncontaminated. The drainage system must be kept closed or pumps turned off unless the drainage process is monitored.

8. Materials that in combination may cause a fire or explosion, or the production of a flammable, toxic, or poisonous gas, or the deterioration of a primary or secondary container shall be separated in both the primary and secondary containment to avoid intermixing.

9. If the tank is a vertical tank and has a leak in the middle, the dyke should be constructed in such a way that it considers the traveling distance of the material due to its head.

These are universal practices.

Apart from this, I don't have the answer for the question "kindly specify where it is mentioned (ACT/Rule etc.)" If you want the rules, I'm helpless and will try to look into this, but not immediately, as I'm unable to concentrate on this.

Yesterday, I missed your thread, and so, once again, a late sharing of the points. Kindly bear with me.

Dear Tgpenney, thank you for the inputs.

Dear Dipil, I need to have a look at your link.

Dear Srinivas, could you please tell me where you got this 1.25 from? This point is new to me.

Hope Abhay can get something out from this explanation.

Mr. SRINIVASAN

Is absolutely right about the 1.25 holding cap. This allows for the chemical to be held, plus a contamination factor of water.

Additionally, another important aspect to consider is whether the other chemicals in the holding area can be mixed. Are they compatible if mixed together, or will they react with water if they leak, especially after rain? The same consideration applies to acid-based products. Some chemicals may require a secondary containment wall or area.

It is crucial to always review and revise all emergency response plans and fire control plans to ensure quick and effective control.

The US Chemical Safety Board is a valuable source for this type of data. They emphasize the importance of checking all exterior piping and conducting a thorough risk assessment, including tank breather valves and hatch lids. They have an excellent video on this topic in their library of materials.

Alberta and California have some of the best data on chemicals and berm or dyke operations, which can serve as examples for construction purposes. I'm sure your own country has its own chemical, dangerous goods, hazmat department with local or provincial guidelines.

Most insurance companies have their own set of guidelines in place due to insurance reviews.