diff --git a/src/org/addition/epanet/hydraulic/HydraulicAndQualitySim.java b/src/org/addition/epanet/hydraulic/HydraulicAndQualitySim.java
new file mode 100644
index 0000000..5b24ac6
--- /dev/null
+++ b/src/org/addition/epanet/hydraulic/HydraulicAndQualitySim.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2012  Addition, Lda. (addition at addition dot pt)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/.
+ */
+package org.addition.epanet.hydraulic;
+
+import java.io.IOException;
+import java.util.logging.Logger;
+
+import org.addition.epanet.hydraulic.io.AwareStep;
+import org.addition.epanet.network.Network;
+import org.addition.epanet.network.PropertiesMap;
+import org.addition.epanet.quality.QualitySim;
+import org.addition.epanet.util.ENException;
+
+/**
+ * Hybrid Hydraulic and Water Quality simulation class.
+ */
+public class HydraulicAndQualitySim extends HydraulicSim {
+
+    /**
+     * Optional related QualitySim when Water Quality analysis is needed.
+     */
+    private QualitySim qualitySim;
+
+    /**
+     * Init hydraulic simulation, preparing the linear solver and the hydraulic structures wrappers.
+     *
+     * @param net Hydraulic network reference.
+     * @param log Logger reference.
+     * @throws ENException
+     */
+    public HydraulicAndQualitySim(Network net, Logger log) throws ENException {
+        super(net, log);
+        if (!net.getPropertiesMap().getQualflag().equals(PropertiesMap.QualType.NONE)) qualitySim = new QualitySim(net, log);
+    }
+
+    /**
+     * Write the simulation results to current output.
+     */
+    @Override
+    protected void writeSimulationOutput() throws ENException, IOException {
+        if (simulationOutput != null && qualitySim != null) {
+            AwareStep.writeHydAndQual(simulationOutput, this, qualitySim, Rtime-Htime, Htime);
+            return;
+        }
+        super.writeSimulationOutput();
+    }
+
+    /**
+     * Finds length of next time step & updates tank levels and rule-based control actions.
+     */
+    @Override
+    protected long nextHyd() throws ENException, IOException {
+        long hydstep = super.nextHyd();
+
+        if (qualitySim != null) {
+            for (long i = 0, qstep = pMap.getQstep(), numQsteps = hydstep/qstep; i < numQsteps; i++) {
+                qualitySim.simulateSingleStep(nNodes, nLinks, qstep);
+            }
+        }
+        return hydstep;
+    }
+}
diff --git a/src/org/addition/epanet/hydraulic/HydraulicSim.java b/src/org/addition/epanet/hydraulic/HydraulicSim.java
index 88dd8a2..dd6f0d7 100644
--- a/src/org/addition/epanet/hydraulic/HydraulicSim.java
+++ b/src/org/addition/epanet/hydraulic/HydraulicSim.java
@@ -686,13 +686,20 @@ private void computeDemands() throws ENException {
     }
 
     /**
-     * Finds length of next time step & updates tank levels and rule-based contol actions.
+     * Write the simulation results to current output.
+     */
+    protected void writeSimulationOutput() throws ENException, IOException {
+        if (simulationOutput != null)
+            AwareStep.write(simulationOutput, this, Htime);
+    }
+
+    /**
+     * Finds length of next time step & updates tank levels and rule-based control actions.
      */
     protected long nextHyd() throws ENException, IOException {
         long hydstep = 0;
 
-        if (simulationOutput != null)
-            AwareStep.write(simulationOutput, this, Htime);
+        writeSimulationOutput();
 
         if (Htime < pMap.getDuration())
             hydstep = timeStep();