Petrol pumps to check tanks for water ‘every 2-8 hours’: Officials

Petrol pumps are being told to test underground storage tanks and dispensing nozzles for water because E20 is more vulnerable to water contamination than ordinary petrol. The aim is to protect fuel quality before contaminated petrol reaches customers. The required interval varies with operating shifts and weather, ranging from two to eight hours.

The test uses an alcohol-resistant water-finding paste. If water enters E20, ethanol absorbs it and separates from the petrol. The ethanol and water then form a distinct layer at the tank’s bottom. This process is called phase separation. Testing helps dealers detect water ingress early and respond before the fuel becomes unsuitable for sale.

IOC and HPCL outlets generally test every two to four hours, while BPCL has revised its interval to every eight hours. BPCL requires at least three checks daily at 24-hour outlets and two at shorter-hour outlets. The rules potentially affect more than 93,000 OMC pumps nationwide.

E20 means ethanol-blended petrol containing 20% ethanol. The article describes this fuel as ethanol-blended motor spirit, or EBMS. Because ethanol is highly hygroscopic, it readily absorbs water from its surroundings. That makes water control especially important as petrol pumps handle increasingly large volumes of E20.

When water enters E20, the ethanol draws the water into the fuel. The ethanol then separates from the petrol and forms a distinct water-ethanol layer at the bottom of the storage tank. This change is called phase separation. A water-finding paste can help dealers detect water in tanks and at dispensing nozzles before contaminated fuel is sold.

The article reports that blending reached 20% from November 2025 to March 2026, during the first five months of ESY 2025-26. That rising use explains the focus on frequent checks. OMCs and dealers are both expected to protect the quality of ethanol-blended petrol.

The testing frequency is not identical everywhere. Most IOC and HPCL retail outlets reportedly check tanks and nozzles every two to four hours. BPCL recently revised its procedure to require checks every eight hours. Its letter requires at least three checks at outlets operating 24 hours and two checks at outlets operating for less than 24 hours.

The rules apply across a very large retail network. As of April 1, 2026, IOC, BPCL and HPCL operated 93,239 petrol pumps. IOC operated 42,818, BPCL 25,323 and HPCL 25,098. Private companies operated another 9,784 pumps, but the article focuses on the three state-run OMCs.

Therefore, the rules could affect fuel quality for customers visiting more than 93,000 OMC outlets. The article does not provide a figure for the number of customers served. It also reports that IOC had described inspections at about 90,000 outlets as occurring eight to twelve times daily.

When water contaminates E20, the ethanol absorbs it and separates from the petrol. A distinct water-ethanol layer settles at the bottom of the storage tank. The immediate result, covered by the article, is phase separation and fuel contamination. Such fuel no longer has the intended, uniform ethanol-petrol composition and should not be sold.

The article does not describe specific damage to storage tanks or vehicle engines. In established fuel-system knowledge, water left in a tank can promote corrosion, while the separated layer can be drawn into pumps and fuel systems. In an engine, contaminated fuel may cause hard starting, misfiring, loss of power or stalling because water and uneven fuel composition disrupt combustion.

The practical response is early detection. Dealers use alcohol-resistant water-finding paste to check tanks and nozzles. More frequent testing is intended to catch water ingress before contaminated E20 reaches customers. The OMC guidelines make both companies and dealers responsible for selling fuel of the correct quality.

Ethanol absorbs water more readily than ordinary petrol because it is hygroscopic. In simple terms, ethanol has a strong attraction to water and can take up moisture from the surrounding air or from water entering storage equipment. Petrol itself does not behave in the same way, so adding ethanol creates a greater need for moisture control.

Rainy or humid conditions can increase the amount of moisture around tanks, delivery equipment and dispensing systems. If that water reaches E20, ethanol absorbs it and separates from the petrol. The mixture then forms a water-ethanol layer at the bottom of the tank. Alcohol-resistant water-finding paste is used to detect this contamination.

The article reports that the new instructions came as rains affected parts of India. It does not provide a measured humidity threshold or quantify how much additional water enters tanks during rain. Instead, it links the weather risk with more frequent testing, ranging from every two to eight hours depending on shifts and conditions.

Both the oil marketing companies and petrol-pump dealers are responsible for preventing contaminated E20 from reaching customers. The Marketing Discipline Guidelines say oil companies must market ethanol blended according to government guidelines. They also say dealers must ensure that the correct-quality ethanol-blended product is sold in the market.

The responsibilities cover different points in the supply chain. Locations undertaking ethanol blending must mix it within prescribed limits and check for ethanol before releasing the product. Dealers then operate retail outlets, inspect tanks and nozzles for water, and follow the required procedures. These checks help detect water ingress and prevent phase separation.

This shared responsibility matters because contamination can arise during storage or handling, while incorrect blending can occur earlier. The article reports that the three OMCs issued or implemented more frequent checking procedures. It also notes that both OMCs and dealers can be held responsible for selling contaminated fuel under the guidelines.

The article documents the rapid growth of ethanol blending but does not explain why policymakers chose it. Ethanol is a renewable alcohol fuel that can replace part of the petrol volume in a blend. In established energy policy, this can reduce reliance on fossil petrol, support domestic agricultural or biofuel production, and potentially lower some emissions, depending on how ethanol is produced.

The article’s clearest evidence is the blending increase. Ethanol blending rose from 14.6% in ESY 2023-24 to 19.2% in ESY 2024-25. It reached 20% from November 2025 through March 2026, the first five months of ESY 2025-26. That 20% blend is called E20.

The higher blend also creates a practical challenge. Ethanol readily absorbs water, so pumps need tighter monitoring to prevent phase separation. The article connects the growth in E20 with frequent tank and nozzle checks, but it does not quantify reductions in imports, emissions or petrol consumption.