missing import

cgevans · cgevans · commit 185c1fd1bce9 · 2025-10-29T17:08:05.000-07:00
diff --git a/src/riverine/references.py b/src/riverine/references.py
@@ -18,6 +18,7 @@
     DecimalQuantity,
     _parse_conc_optional,
     _parse_conc_required,
+    NAN_CONC,
     nM,
     ureg,
 )
