Sustainable Aquaculture Infrastructure with Ocean HDPE Liner 500 Micron at ICAR-National Research Centre for Makhana (NRCM), Darbhanga, Bihar

Introduction

At the ICAR-National Research Centre for Makhana (NRCM) in Darbhanga, Bihar, Ocean Non Wovens supplied and installed 2100 SQM of Ocean HDPE Liner 500 Micron to line ponds used for makhana cultivation and water containment.

Makhana (fox nut) is grown in standing water, and north Bihar produces most of India’s crop. The plant needs a controlled water level through its growing season, which is hard to hold in an earthen pond: in permeable soil, stored water seeps away and has to be topped up constantly, and the water level, and with it growing conditions, keeps shifting. For a research centre running cultivation trials, an unstable water level also muddies the results. A HDPE geomembrane liner removes the seepage path.

Project overview

• Project name: ICAR-National Research Centre for Makhana (NRCM)
• Location: Darbhanga, Bihar
• Product used: Ocean HDPE Liner 500 Micron
• Quantity: 2100 SQM
• Scope: Supply & installation
• Application area: Aquaculture and water containment infrastructure

The liner had to hold water through continuous submersion, biological activity in the pond, UV exposure on the slopes above the waterline, and Bihar’s seasonal temperature swings.

Why line a makhana pond

How much an unlined pond loses to seepage depends mostly on the soil. In sandy or silty ground the loss can be large enough to make the pond hard to run at all. Stable water levels matter because they control crop growth conditions, nutrient stability, water quality and biological productivity, and because a saturated embankment slowly weakens.

A geomembrane liner addresses each of these:

• Water retention: the liner stops seepage into the subgrade, so the pond needs far less replenishment.
• Pond management: a steady water level gives consistent cultivation conditions, which matters for research plots at a facility like NRCM.
• Soil protection: without constant seepage the surrounding soil stays drier, so embankments are less prone to slumping.
• Maintenance: earthen ponds need regular repair after erosion, seepage and settlement. Lined ponds need less, and behave more predictably.

Why Ocean HDPE Liner 500 Micron was selected

Liner thickness depends on exposure, water depth, subgrade, how the pond will be used and budget. 500 micron (0.5 mm) is the lightest grade covered by IS 16352, the BIS specification for HDPE lining geomembranes, which runs from 0.5 mm to 3.0 mm. For shallow cultivation ponds on a well-prepared subgrade, it gives a practical balance of flexibility, durability and ease of installation.

• Flexibility: the 500 Micron sheet conforms closely to pond geometry and minor surface irregularities.
• UV resistance: carbon black in the HDPE protects the exposed slopes from sunlight.
• Chemical resistance: pond water carries organic matter, nutrients and dissolved salts. HDPE is inert to all of these.
• Low permeability: an intact HDPE sheet is effectively impermeable to water.
• Handling: lighter rolls are quicker to deploy and position on soft ground.

Site challenges

Soft soil

Parts of the Darbhanga area have soft, moisture-sensitive alluvial soils that lose strength during excavation. Careful grading and subgrade preparation were needed before the liner went down.

Continuous submersion and biological activity

A cultivation pond liner stays under water for long periods, so seam quality and material durability carry more weight than on a temporary containment. Roots, organic sediment and pond organisms are constantly in contact with the sheet. HDPE is not biodegradable, but a poorly made or under-stabilised sheet will age faster in these conditions.

Heat, UV and wrinkling

Bihar summers bring high temperatures and strong sunlight. HDPE expands as it heats and contracts as it cools, so a sheet laid and anchored at midday can wrinkle, and a sheet locked down in the morning can pull tight later. Wrinkles concentrate stress, and a liner in tension bridges over hollows. Installers manage this by timing deployment and seaming and leaving controlled slack.

Installation and quality control

Even a well-made geomembrane fails early if it is badly installed. The NRCM work followed the standard sequence:

• Surface grading and levelling
• Removal of stones, roots and sharp protrusions
• Controlled liner deployment
• Anchoring at the crest
• Seam welding and inspection
• Wrinkle management
• Quality testing

Seams are the most likely leak path. Field seams are checked by air-pressure testing of dual-track wedge welds and vacuum-box testing of extrusion welds and patches. The liner is anchored in a perimeter trench so that wind, thermal movement or water pressure cannot drag it down the slope or lift it; poor anchoring is a common cause of early failure in lined ponds.

Long-term performance

Service life depends on UV exposure, biological activity, water chemistry, mechanical stress, installation quality, drainage and maintenance. Drainage beneath the liner is easy to overlook. If groundwater collects under the geomembrane with no way out, it can lift the liner when the pond is drawn down. In areas with a high water table, such as much of north Bihar, under-liner drainage or pressure relief should be part of the pond design.

Compared with an earthen pond, a lined pond loses less water to seepage, suffers less embankment erosion and weakening, needs fewer repairs and keeps a steadier water level. That means lower maintenance spend, less water drawn and more consistent cultivation.

Where else this applies

The same geosynthetics line fish farming ponds, makhana cultivation ponds, reservoirs, canals, irrigation ponds, water harvesting tanks and effluent containment. See the geomembranes range for other thicknesses, and our case studies for comparable pond projects.

About Ocean Non Wovens

Ocean Non Wovens manufactures and supplies geosynthetics for aquaculture, irrigation, landfill, environmental, industrial and infrastructure projects across India, with manufacturing, supply and installation support.