diff --git a/python/Dockerfile b/python/Dockerfile
index 336851f5..eacdf0df 100644
--- a/python/Dockerfile
+++ b/python/Dockerfile
@@ -11,4 +11,4 @@ RUN chmod +x add_data.sh && \
     apt-get update && \
     apt-get install -y eatmydata git git-lfs jq time
 #ENTRYPOINT ["/usr/src/app/docker-entrypoint.sh"]
-CMD ./add_data.sh ${POSTGRES_USER} ${POSTGRES_PASS} ${POSTGRES_PORT} ${DB_NAME} ${POSTGRES_HOST} ${ES_ENDPOINT} ${ES_USER} ${ES_PASS} ${KIBANA_ENDPOINT}
+CMD ./add_data.sh
diff --git a/python/add_data.sh b/python/add_data.sh
index 67f929a1..4d96efd0 100755
--- a/python/add_data.sh
+++ b/python/add_data.sh
@@ -11,16 +11,14 @@
 trap : TERM INT
 set -e
 
-POSTGRES_USER=$1
-POSTGRES_PASS=$2
-POSTGRES_PORT=$3
-DB_NAME=$4
-POSTGRES_HOST=$5
-
-ES_ENDPOINT=$6
-ES_USER=$7
-ES_PASS=$8
-KIBANA_ENDPOINT=$9
+# Needed variables (defined in .env for Docker Compose, or in a Amazon ECS task definition)
+ENV_VAR_LIST=(
+  POSTGRES_USER POSTGRES_PASS POSTGRES_PORT POSTGRES_HOST DB_NAME
+  POPULATE_DB \
+  KIBANA_ENDPOINT ES_ENDPOINT ES_USER ES_PASS \
+  loadDsraScenario loadPsraModels loadHazardThreat loadPhysicalExposure
+  loadRiskDynamics loadSocialFabric
+)
 
 DSRA_REPOSITORY=https://github.com/OpenDRR/scenario-catalogue/tree/master/FINISHED
 
@@ -314,6 +312,21 @@ merge_csv() {
 #######################     Begin main processes                     #######################
 ############################################################################################
 
+LOG "# Begin main processes"
+
+LOG "## Check needed environment variables"
+
+for var in "${ENV_VAR_LIST[@]}"; do
+  INFO "$var = ${!var}"
+  if [[ -z ${!var} ]]; then
+    if [[ "$var" =~ ^(ES_USER|ES_PASS)$ ]]; then
+      INFO "$var is not set, but it is optional"
+    else
+      WARN "$var is mandatory but not set!  Your build will likely fail!"
+    fi
+  fi
+done
+
 # Speed up file writes with eatmydata
 LD_LIBRARY_PATH=${LD_LIBRARY_PATH:+"$LD_LIBRARY_PATH:"}/usr/lib/libeatmydata
 LD_PRELOAD=${LD_PRELOAD:+"$LD_PRELOAD "}libeatmydata.so
diff --git a/sample.env b/sample.env
index 6494f4a4..e7be8467 100644
--- a/sample.env
+++ b/sample.env
@@ -1,3 +1,5 @@
+# Sample .env file used by Docker Compose for python-opendrr service
+
 POSTGRES_USER=postgres 
 POSTGRES_PASS=password
 POSTGRES_PORT=5432
@@ -7,6 +9,7 @@ POPULATE_DB=0
 
 KIBANA_ENDPOINT=http://kibana-opendrr:5601
 ES_ENDPOINT=http://elasticsearch-opendrr:9200
+# ES_USER and ES_PASS are optional (can be empty) for local builds
 ES_USER=
 ES_PASS=