We introduce CnC-Scala (CS), a pure Scala implementation of Intel's Concurrent Collections programming model. Extracting parallelism from applications often involves the use of low-level primitives such as locks and threads, and the associated problems of data races and nondeterminism. In contrast, CS allows programmers to express their application logic using a graphical coordination language to compose units of sequential Scala code, with control and data dependences expressed in a simple declarative manner. Thus, CS makes parallel programming accessible to a broad class of programmers who are not trained in parallel programming. Given these declarative constraints, it is the responsibility of the compiler and runtime system to extract parallelism and performance from the application, for a given hardware platform. CS is implemented using a new Scala-based runtime system based on one-shot delimited continuations to avoid thread blocking operations.