Under NEC Option B how to assess and quantify compensation event claims with potential underlying weather cause

Under a NEC4 Option B contract 3 separate CE’s have been notified that are intrinsically linked. The site is a sloping site with large amounts of excavation and removal of earth as part of the scope together with the retention of some excavated material for use as backfill to behind retaining structures once installed. Temporary retaining works formed a Contractor Design package to enable the subsequent construction of the waterproof retaining structure forming part of the main building. The first CE notified relates to costs associated with contractor designed dewatering relative to the temporary kingpost retaining structure of the CDP works, this was identified as a cost risk item at pre-contract stage. A second CE was notified as a weather event for excessive rainfall which does meet the criteria for that month with the excess approximately 4 days over the 1 in 10 year event, as part of this CE it was also highlighted that a number of site factors had been affected by the weather including the washing away of part of a stone mud mat installed by the contractor across the site as part of their site set up (not part of the scope), additional wheel washing and road sweeping due to excessive mud distribution from vehicle movements from the site, and a quantity of the excavated material stored for backfilling had become saturated and was removed from site. Each of these additional consequences has been included in the quotation relating to this second CE. A third CE has been notified advising that further quantities of excavated materials stored for backfilling had been removed from site due to saturation, these over and above the extent identified for removal in the scope. This last CE and associated EWN were notified after the event with no opportunity afforded to review before the material was removed with programme cited as justification on the Contractors behalf. All these CE’s are related to weather and water specifically. What process is typically followed to assess and quantify these claims and to what extent each is over and above the expected actions of the contractor under normal expected weather conditions?

Difficult question and the devil will be in the detail.

On the information in the question, the first CE notified does not appear to be a CE. The fact that the Contractor got the costs wrong (up or down) is in itself not a CE. I’m not sure if the question relates to the weather event, as opposed to costing, if it does the following will apply.

The principle of a weather CE is that the assessment should be based on the extra over ie the Contractor takes the risk of the weather up to the 1 in 10. The types of cost heads you refer to appear to be valid but the crux is which costs are extra over and needs a detailed review.

The third CE appears to be directly linked to the weather CE and should therefore be considered as part of the weather event assessment. If it is not attributable to the weather event then it is not a CE.

Thank you for your feedback Dave. To clarify, the dewatering works identified in the first CE were omitted from the original contractors tender with a risk budget set aside to cover contractors costs following development of the design post contract award. The reason I include this CE in the query was that this related to dewatering of the temporary retaining works and that the subsequent CE’s highlight water as the cause. With regards the second CE, would extra over costs as a result of the weather over the 1 in 10 year standard extend to elements such as reinstatement of the mud mat across the site which was originally installed by contractor as part of their own site set up and not part of the scope? The 3rd CE occurs in a separate month to the weather event of the 2nd CE, no weather event has been notified for the month in question for the 3rd CE. Some saturated excavated material was removed from site following the 2nd CE and then further saturated materials removed from site at a later date form the basis of the 3rd CE.

The assessment of the first CE will depend upon the contract wording and intent around the risk item.

For the second CE, yes the additional cost should be considered on the basis that it is cost that would not had been incurred had the CE not occurred. To emphasis, it is the additional cost.

If no weather event occurred to cause the third CE then there is no (third) CE to assess. Unless the Contractor is saying that the further saturated material was related to the acknowledged CE and is an extra over then there is nothing to assess. If the second CE has been implemented then again there is nothing to assess.

Thanks again for your input. In relation to the 3rd CE, the removal of material was considered not related to a weather event due to a number of months between the last recorded weather event and the removal of the soil from site. The CE was duly therefore not accepted. The decision has however been challenged by the Contractor on the basis that the physical conditions they refer to relate to the cohesive nature of the clay sub-soil prevailing on site – about which the Site Information states: ‘It is important that bulk excavations and placement of clay fill be undertaken, insofar as is possible, during the summer months since handling of clay soils in wet weather will render these soils unsuitable for reuse’. Would it therefore be conceivable that a proportion of the excavated material would become unsuitable even under ‘normal’ winter conditions as a consequence of its inherent physical characteristics invoking Clause 60.1(12) as a reason for a valid CE claim?

If I am understanding your query correctly the matter is around the nature of the excavated material being different to that which could have been foreseen and not that the material has been effected by the weather.

Given the extract from the Site Information (which should have been considered at tender) it would appear that the nature of the material should have been known and that it would need protecting/managing in wet weather. Therefore the situation was reasonably foreseeable and not unforeseen/have a small chance of occurring. The Site Information does however need to be consider in conjunction with other information see clause 60.2. Hope that helps