We consider a scalar conservation law with source in a bounded open interval $$\Omega \subseteq \mathbb R$$
Ω
⊆
R
. The equation arises from the macroscopic evolution of an interacting particle system. The source term models an external effort driving the solution to a given function $$\varrho $$
ϱ
with an intensity function $$V:\Omega \rightarrow \mathbb R_+$$
V
:
Ω
→
R
+
that grows to infinity at $$\partial \Omega $$
∂
Ω
. We define the entropy solution $$u \in L^\infty $$
u
∈
L
∞
and prove the uniqueness. When V is integrable, u satisfies the boundary conditions introduced by F. Otto (C. R. Acad. Sci. Paris, 322(1):729–734, 1996), which allows the solution to attain values at $$\partial \Omega $$
∂
Ω
different from the given boundary data. When the integral of V blows up, u satisfies an energy estimate and presents essential continuity at $$\partial \Omega $$
∂
Ω
in a weak sense.