Kentish Ragstone Aggregate Supply

The Environment Agency is seeking early engagement with suppliers for the supply of natural stone aggregate for embankment repairs to the tidal River Ouse embankments in East Sussex between Newhaven and the A27 (near Lewes). The banks of the tidal River Ouse were raised in the fifties and the exposed face was protected from scour at high tide by a revetment know as pole wharfing. The revetment consists of chestnut stakes and woven chestnut poles retaining limestone cobbles.

Approximately 1,000 - 2,000 tonnes of aggregate each year (from 2015 to 2024) are expected to be used for polewharfing and as gabion fill material.

The average annual quantity of aggregate is likely to be around 200 tonnes however this figure could vary from year to year as the work is dependent on the condition of the embankments.

Work is typically restricted to between April and September to coincide with the favourable ground conditions (although emergency repairs may be required outside of this period).

The work is necessary to enable the Environment Agency to comply with its legal obligations under the Newhaven Navigation Act 1847 and has resulted from the approved River use to Seaford Head Coastal Defence Strategy.

Material Specification:

The aggregate supplied for the Contract will need to match with the existing natural stone aggregate already in place along the tidal River Ouse embankments which is Kentish Ragstone, a sandy limestone aggregate. All material supplied under the Contract must be suitable for the intended purpose (as a tidal riverbank revetment or gabion stone). The material shall be hard quarried rock, extremely durable, frost proof and non-degradable.

Please note, The detailed aggregate specification, the Environment Agency will only accept interest from potential suppliers who can evidence the supply of the raw aggregate material that can meet the specification in Table 1 below.

Material Specification.

Aggregate size (mm) 100 - 200

Colour: Medium Grey on BRE Colour Chart, Grey on Munsell Rock Colour chart, or equivalent

Compressive Strength, Strong - Very Strong (50MPa-250MPa)

Durability - Resistance to weathering and low frost susceptibility

Table 1 - Aggregate Specification

The Contractor will ensure that the quarry from which the material is sourced has the appropriate planning permission (issued by the relevant Minerals Planning Authority), with appropriate Environmental Statement/Environmental Impact Assessment in place.

Geographical Coverage:

The aggregate is to be supplied and delivered to any of four sites covering the geographical area between Lewes and Newhaven in East Sussex. Please refer to delivery addresses below:

Piddinghoe sailing club (BN99AX) - TQ4377402740

Southease Depot - (BN73HX) - TQ4284305366

Beddinhgam PS (BN86JY) - TQ4441808064

Southerham Bridge (BN72BS) - TQ4248809283