--- a/pkg/controllers/fwa.go	Sat Aug 21 15:01:52 2021 +0200
+++ b/pkg/controllers/fwa.go	Mon Sep 20 17:45:39 2021 +0200
@@ -18,7 +18,6 @@
 	"database/sql"
 	"encoding/csv"
 	"fmt"
-	"log"
 	"net/http"
 	"sort"
 	"strconv"
@@ -28,6 +27,7 @@
 	"github.com/gorilla/mux"
 
 	"gemma.intevation.de/gemma/pkg/common"
+	"gemma.intevation.de/gemma/pkg/log"
 	"gemma.intevation.de/gemma/pkg/middleware"
 )
 
@@ -219,7 +219,7 @@
 	}
 
 	if err != nil {
-		log.Printf("error: %v\n", err)
+		log.Errorf("%v\n", err)
 		http.Error(rw, "cannot extract bottlenecks", http.StatusBadRequest)
 		return
 	}
@@ -233,19 +233,19 @@
 	// load validities and limiting factors
 	for i := range bns {
 		if err := bns[i].loadLimitingValidities(ctx, conn, from, to); err != nil {
-			log.Printf("error: %v\n", err)
+			log.Errorf("%v\n", err)
 			http.Error(rw, "cannot load validities", http.StatusInternalServerError)
 			return
 		}
 		// load LCDs
 		if err := bns[i].loadLDCs(ctx, conn, from, to); err != nil {
-			log.Printf("error: %v\n", err)
+			log.Errorf("%v\n", err)
 			http.Error(rw, "cannot load LDCs", http.StatusInternalServerError)
 			return
 		}
 		// load values
 		if err := bns[i].loadValues(ctx, conn, from, to, los); err != nil {
-			log.Printf("error: %v\n", err)
+			log.Errorf("%v\n", err)
 			http.Error(rw, "cannot load values", http.StatusInternalServerError)
 			return
 		}
@@ -300,7 +300,7 @@
 
 	if err := out.Write(record); err != nil {
 		// Too late for HTTP status message.
-		log.Printf("error: %v\n", err)
+		log.Errorf("%v\n", err)
 		return
 	}
 
@@ -417,7 +417,7 @@
 		if finish(next) {
 			if err := write(); err != nil {
 				// Too late for HTTP status message.
-				log.Printf("error: %v\n", err)
+				log.Errorf("%v\n", err)
 				return
 			}
 
@@ -435,14 +435,14 @@
 	if totalDays > 0 {
 		if err := write(); err != nil {
 			// Too late for HTTP status message.
-			log.Printf("error: %v\n", err)
+			log.Errorf("%v\n", err)
 			return
 		}
 	}
 
 	for i, days := range missingLDCs {
 		if missingLDCs[i] > 0 {
-			log.Printf("warn: Missing LDCs for %s on %d days.\n",
+			log.Warnf("warn: Missing LDCs for %s on %d days.\n",
 				bns[i].id, days)
 		}
 	}
@@ -450,7 +450,7 @@
 	out.Flush()
 	if err := out.Error(); err != nil {
 		// Too late for HTTP status message.
-		log.Printf("error: %v\n", err)
+		log.Errorf("%v\n", err)
 	}
 }
 
@@ -526,7 +526,7 @@
 	defaults, err := breaksToReferenceValue(breaks)
 	if err != nil {
 		msg := fmt.Sprintf("Parameter '%s' is invalid: %s.", parameter, err)
-		log.Printf("error: %s\n", msg)
+		log.Errorf("%s\n", msg)
 		http.Error(rw, msg, http.StatusBadRequest)
 		return nil, false
 	}
@@ -586,7 +586,7 @@
 	case "width":
 		return limitingWidth
 	default:
-		log.Printf("warn: unknown limitation '%s'. default to 'depth'\n", limiting)
+		log.Warnf("unknown limitation '%s'. default to 'depth'\n", limiting)
 		return limitingDepth
 	}
 }