The question behind the question
Owners rarely ask "EPC or package?" in the abstract. The question arrives in a more practical form: who carries the risk when the design is wrong, who resolves the clash at the battery limit, and who is answerable when the terminal does not achieve its throughput on the day of the performance test.
Full EPC and defined-scope package delivery answer those three questions differently. The engineering content of a tank farm does not change between the two models. What changes is where the risk sits, how many contractual interfaces exist, and who owns the gaps between them.
Full EPC: one contract, one accountable party
Under a full EPC contract a single contractor takes engineering, procurement and construction for a defined facility. The commercial attraction is singular accountability: the Employer has one party to hold to a completion date and one party to hold to a performance guarantee.
Three points are commonly misread.
Single-point responsibility is not unlimited responsibility. It attaches to the defined scope. Employer-retained items, typically site data, geotechnical information, permits, free-issue material, utility tie-in points and third-party approvals, remain the Employer's risk unless the contract expressly transfers them.
The price basis carries the risk allocation, not the acronym. A lump-sum turnkey EPC transfers quantity and productivity risk to the contractor. A reimbursable or target-cost EPC does not. Both are EPC.
The contractor inherits the FEED. Where the Employer supplies a FEED prepared by others and the EPC contractor is required to take design responsibility for it, the contractor is carrying design it did not originate. Whether the contractor also performed the FEED is therefore one of the more consequential facts about any EPC award.
Chemie-Tech delivered the ATLS multi-product petroleum storage terminal at Djibouti Oil Port on that basis: concept development and FEED followed by EPC execution, for a planned 285,000 m³ terminal comprising 8 tanks across a 21-hectare site. Where the same contractor develops the concept, sets the design basis and then builds against it, the interface between design intent and constructed asset is internal rather than contractual. That is the practical value of the model.
Defined-scope packages: bounded scope, managed interfaces
On large refinery and petrochemical programmes the Employer or a prime EPC contractor splits the facility into packages and appoints specialists to each. A tank farm is a natural package: it is a distinct discipline, it has a long procurement lead, and its construction sequence differs from process units.
The package contractor's scope is bounded and its risk profile is narrower. Its exposure moves elsewhere, into interface management.
Chemie-Tech delivered the T1 and T2 tank farm package on the Basrah Refinery Upgrading project in Iraq, comprising 50 tanks with a maximum diameter of 57 m, executed within the prime EPC framework led by HDEC and JGC. At the Dangote Refinery and Petrochemical complex in the Lekki Free Trade Zone, Lagos, Chemie-Tech’s scope covered Tankage Packages I to III, comprising 154 tanks with an aggregate capacity of 36.8 million bbl and a maximum diameter of 92 m.
Neither of those scopes was won on tank engineering alone. Both depended on the discipline of working inside somebody else's programme.
What interface management actually means
"Interface management" is used loosely. On a package scope it has a specific and largely administrative content.
Document control. The prime's numbering, transmittal and review cycle governs. A package contractor working to its own document conventions will lose weeks in re-submission. Submittal turnaround times are a schedule input and belong in the contract.
Physical tie-in points. Every line, cable, road and drain crossing the package boundary must be defined by coordinate, elevation, size, specification and the party responsible either side. Undefined tie-ins become variations.
Scope gaps between packages. The most expensive item on a multi-package project is usually the work nobody priced: firewater ring main between two package boundaries, cathodic protection continuity, the foundation for a shared pipe rack. Scope-gap risk is created at tender stage by the Employer's package split and discovered at construction stage.
Shared site resources. Craft labour, laydown area, cranage, accommodation and permit-to-work all sit under the prime's control. Availability is a schedule risk the package contractor carries but does not control.
Schedule interdependency. Where the prime holds the master programme, the package contractor's float is not its own. Delay arising upstream will affect the package, and whether time or cost can be recovered depends on the terms agreed at subcontract stage.
Choosing the model
The decision is the Employer's and is driven by four factors.
Scale and scope split. A standalone terminal is a natural full-EPC scope. A refinery complex with process units, utilities, offsites and tankage is normally packaged.
Risk appetite and price certainty. Lump-sum EPC buys price certainty and pays a premium for it. Packaging retains more risk with the Employer and requires the Employer, or a prime, to carry the integration function.
Owner's own capability. Packaging only works where somebody has the engineering and project-controls capacity to manage the interfaces. Where the Employer does not have that capacity in-house, the integration risk does not disappear; it becomes unmanaged.
Schedule. Packaging permits parallel award of long-lead scopes and can compress the programme, provided the interface definition is mature enough at award to allow it.
| Full EPC | Defined-scope package | |
|---|---|---|
| Contractual interfaces | One | Many, managed by prime or Employer |
| Design responsibility | Contractor, subject to FEED carve-outs | Bounded to the package, tie-ins defined by others |
| Principal risk to contractor | Quantity, productivity, performance | Interface, submittal cycle, upstream delay |
| Principal risk to Employer | Price premium, change control | Scope gaps, integration |
| Suits | Standalone facilities and terminals | Large complexes with split specialist scopes |
Where Chemie-Tech sits
Chemie-Tech works in both models. On full EPC scopes the position is strongest where the concept and FEED are also ours, as at Djibouti. On package scopes the deliverable is not only the tankage but the discipline of aligning with the prime's systems, as on Basrah under HDEC and JGC and across Tankage Packages I to III at Dangote.
The failure mode to avoid is a contract labelled EPC that is executed as a package, or a package priced as though its interfaces were the Employer's problem. The model should be settled before the scope is priced.
Common Questions
Does a full EPC contract always cost more?
It usually carries a premium for the risk transferred. Whether it costs more in total depends on the Employer's own capacity to manage interfaces and change; the premium buys a service the Employer would otherwise have to provide.
Who is responsible for a FEED error under EPC?
It depends on who prepared the FEED and what the contract says about design responsibility for Employer-supplied documents.
What is the single most common problem on a package scope?
Scope gaps at package boundaries, created by the Employer's package split and discovered during construction. They are prevented at tender stage by explicit tie-in schedules.
Can a tank farm be packaged out of an EPC project after award?
It can, and frequently is. The novation or subcontract terms determine whether the risk moves with the scope.