diff --git a/CMakeLists.txt b/CMakeLists.txt
old mode 100755
new mode 100644
index 93fbda1..cc15f07
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -83,8 +83,8 @@ ENDIF (MSVC)
 
 
 # configure file groups
-file(GLOB EPANET_SOURCES RELATIVE ${PROJECT_SOURCE_DIR} src/*.c)
-file(GLOB EPANET_LIB_ALL RELATIVE ${PROJECT_SOURCE_DIR} src/*)
+file(GLOB EPANET_SOURCES RELATIVE ${PROJECT_SOURCE_DIR} src/*.c src/util/*.c)
+file(GLOB EPANET_LIB_ALL RELATIVE ${PROJECT_SOURCE_DIR} src/* src/util/*)
 # exclude epanet python API from the default build
 list(REMOVE_ITEM EPANET_LIB_ALL "src/epanet_py.c")
 source_group("Library" FILES ${EPANET_LIB_ALL})
diff --git a/include/epanet2_2.h b/include/epanet2_2.h
index 051e623..67bf91a 100644
--- a/include/epanet2_2.h
+++ b/include/epanet2_2.h
@@ -165,7 +165,7 @@ typedef struct Project *EN_Project;
   @return an error code
   */
   int  DLLEXPORT EN_setcomment(EN_Project ph, int object, int index, char *comment);
-  
+
   /**
   @brief Retrieves the number of objects of a given type in a project.
   @param ph an EPANET project handle.
@@ -851,7 +851,14 @@ typedef struct Project *EN_Project;
   These properties have units that depend on the units used for flow rate (see @ref Units).
   */
   int  DLLEXPORT EN_setjuncdata(EN_Project ph, int index, double elev, double dmnd,
-                 char *dmndpat);
+      char *dmndpat);
+
+
+  int DLLEXPORT EN_adddemand(EN_Project p, int node_index, double demand,
+      char *demand_pattern, const char *category_name, int *demand_index);
+
+  int DLLEXPORT EN_removedemand(EN_Project p, int node_index, int demand_index);
+
 
   /**
   @brief Sets a group of properties for a tank node.
diff --git a/src/demand.c b/src/demand.c
new file mode 100644
index 0000000..6f005c4
--- /dev/null
+++ b/src/demand.c
@@ -0,0 +1,133 @@
+/*
+ ******************************************************************************
+ Project:      OWA EPANET
+ Version:      2.2
+ Module:       demand.c
+ Description:  data for demand pattern list
+ Authors:      see AUTHORS
+ Copyright:    see AUTHORS
+ License:      see LICENSE
+ Last Updated: 04/12/2019
+ ******************************************************************************
+*/
+
+#ifdef _DEBUG
+  #define _CRTDBG_MAP_ALLOC
+  #include <stdlib.h>
+  #include <crtdbg.h>
+#else
+  #include <stdlib.h>
+#endif
+
+#include <string.h>
+
+#include "demand.h"
+
+
+typedef struct demand_data_s
+{
+  double base_demand;
+  int    pattern_index;
+  char   *category_name;
+} demand_data_t;
+
+
+
+list_t *create_demand_list(double base_demand, int pattern_index, const char *category_name)
+{
+	list_t *demand_list;
+	demand_data_t *demand_data;
+
+	demand_list = create_list(get_demand_data_size(), delete_demand_data);
+	if (!demand_list) return NULL;
+
+	demand_data = create_demand_data(base_demand, pattern_index, category_name);
+	if (!demand_data) return NULL;
+
+	append_list(demand_list, &demand_data);
+
+	return demand_list;
+}
+
+
+demand_data_t *create_demand_data(double base_demand, int pattern_index, const char *category_name)
+{
+    demand_data_t *demand_data = (demand_data_t *)malloc(sizeof(demand_data_t));
+
+    demand_data->base_demand = base_demand;
+    demand_data->pattern_index = pattern_index;
+
+    if (category_name)
+        demand_data->category_name = strdup(category_name);
+    else
+        demand_data->category_name = NULL;
+
+    return demand_data;
+}
+
+void delete_demand_data(void *data)
+{ 
+    demand_data_t *demand_data = *(demand_data_t **)data;
+
+    if (demand_data->category_name)
+        free(demand_data->category_name);
+
+	free(demand_data);
+}
+
+size_t get_demand_data_size(void)
+{
+	return sizeof(demand_data_t *);
+}
+
+demand_data_t *get_demand_data(list_node_t *lnode)
+{
+    return *(demand_data_t **)get_data(lnode);
+}
+
+
+bool convert_units(list_node_t *lnode, double unit_conversion)
+{
+	double base_demand = get_base_demand(lnode);
+
+	set_base_demand(lnode, base_demand/unit_conversion);
+	return true;
+}
+
+
+double get_base_demand(list_node_t *lnode)
+{
+	return get_demand_data(lnode)->base_demand;
+}
+
+void set_base_demand(list_node_t *lnode, double base_demand)
+{
+	get_demand_data(lnode)->base_demand = base_demand;
+}
+
+int get_pattern_index(list_node_t *lnode)
+{
+    return get_demand_data(lnode)->pattern_index;
+}
+
+void set_pattern_index(list_node_t *lnode, int pattern_index)
+{
+	get_demand_data(lnode)->pattern_index = pattern_index;
+}
+
+char *get_category_name(list_node_t *lnode)
+// Be advised: caller must free memory returned
+{
+    char *temp = get_demand_data(lnode)->category_name;
+
+    if (temp)
+        return strdup(temp);
+    else
+        return NULL;
+}
+
+void set_category_name(list_node_t *lnode, const char *category_name)
+{
+	free(get_demand_data(lnode)->category_name);
+	get_demand_data(lnode)->category_name = strdup(category_name);
+}
diff --git a/src/demand.h b/src/demand.h
new file mode 100644
index 0000000..72dd3d8
--- /dev/null
+++ b/src/demand.h
@@ -0,0 +1,63 @@
+/*
+ ******************************************************************************
+ Project:      OWA EPANET
+ Version:      2.2
+ Module:       demand.h
+ Description:  data for demand pattern list
+ Authors:      see AUTHORS
+ Copyright:    see AUTHORS
+ License:      see LICENSE
+ Last Updated: 04/12/2019
+ ******************************************************************************
+*/
+
+#ifndef DEMAND_H
+#define DEMAND_H
+
+
+#include "util/list.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+// Forward declarations
+typedef struct demand_data_s demand_data_t;
+
+// demand list gets declared in types.h struct Snode
+
+
+list_t *create_demand_list(double base_demand, int pattern_index, const char *category_name);
+
+
+demand_data_t *create_demand_data(double base_demand, int pat_index, const char *cat_name);
+
+void delete_demand_data(void *data);
+
+size_t get_demand_data_size(void);
+
+
+bool convert_units(list_node_t *lnode, double unit_conversion);
+
+
+double get_base_demand(list_node_t *lnode);
+void set_base_demand(list_node_t *lnode, double base_demand);
+
+int get_pattern_index(list_node_t *lnode);
+void set_pattern_index(list_node_t *lnode, int pattern_index);
+
+char *get_category_name(list_node_t *lnode);
+void set_category_name(list_node_t *lnode, const char *category_name);
+
+// Make this private?
+demand_data_t *get_demand_data(list_node_t *lnode);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif /* DEMAND_H */
diff --git a/src/epanet.c b/src/epanet.c
index f6c7065..3419097 100644
--- a/src/epanet.c
+++ b/src/epanet.c
@@ -30,6 +30,8 @@
 #include "text.h"
 #include "enumstxt.h"
 
+#include "demand.h"
+
 #ifdef _WIN32
 #define snprintf _snprintf
 #endif
@@ -1719,8 +1721,8 @@ int DLLEXPORT EN_addnode(EN_Project p, char *id, int nodeType, int *index)
     Hydraul  *hyd = &p->hydraul;
     Quality  *qual = &p->quality;
 
-    int i, nIdx, size;
-    struct Sdemand *demand;
+    int i, nIdx;
+    int size;
     Stank *tank;
     Snode *node;
     Scontrol *control;
@@ -1751,12 +1753,7 @@ int DLLEXPORT EN_addnode(EN_Project p, char *id, int nodeType, int *index)
         nIdx = net->Njuncs;
         node = &net->Node[nIdx];
 
-        demand = (struct Sdemand *)malloc(sizeof(struct Sdemand));
-        demand->Base = 0.0;
-        demand->Pat = 0;
-        demand->Name = NULL;
-        demand->next = NULL;
-        node->D = demand;
+		node->D = NULL;
 
         // shift rest of Node array
         for (i = net->Nnodes; i >= net->Njuncs; i--)
@@ -1857,7 +1854,7 @@ int DLLEXPORT EN_deletenode(EN_Project p, int index, int actionCode)
 
     int i, nodeType, tankindex;
     Snode *node;
-    Pdemand demand, nextdemand;
+	list_t *demand;
 
     // Cannot modify network structure while solvers are active
     if (!p->Openflag) return 102;
@@ -1891,13 +1888,9 @@ int DLLEXPORT EN_deletenode(EN_Project p, int index, int actionCode)
 
     // Free memory allocated to node's demands, WQ source & comment
     demand = node->D;
-    while (demand != NULL)
-    {
-        nextdemand = demand->next;
-        free(demand->Name);
-        free(demand);
-        demand = nextdemand;
-    }
+    if (demand)
+        delete_list(demand);
+
     free(node->S);
     free(node->Comment);
 
@@ -2064,7 +2057,6 @@ int DLLEXPORT EN_getnodevalue(EN_Project p, int index, int property, double *val
     Quality *qual = &p->quality;
 
     double v = 0.0;
-    Pdemand demand;
     Psource source;
 
     Snode *Node = net->Node;
@@ -2091,26 +2083,24 @@ int DLLEXPORT EN_getnodevalue(EN_Project p, int index, int property, double *val
 
     case EN_BASEDEMAND:
         v = 0.0;
-        // NOTE: primary demand category is last on demand list
+        // NOTE: primary demand category is first on demand list
         if (index <= nJuncs)
         {
-            for (demand = Node[index].D; demand != NULL; demand = demand->next)
-            {
-                v = (demand->Base);
-            }
+            list_t *demand = Node[index].D;
+            if (demand)
+                v = get_base_demand(head_list(demand, false));
         }
         v *= Ucf[FLOW];
         break;
 
     case EN_PATTERN:
         v = 0.0;
-        // NOTE: primary demand category is last on demand list
+        // NOTE: primary demand category is first on demand list
         if (index <= nJuncs)
         {
-            for (demand = Node[index].D; demand != NULL; demand = demand->next)
-            {
-                v = (double)(demand->Pat);
-            }
+            list_t *demand = Node[index].D;
+            if (demand)
+                v = get_pattern_index(head_list(demand, false));
         }
         else v = (double)(Tank[index - nJuncs].Pat);
         break;
@@ -2265,7 +2255,6 @@ int DLLEXPORT EN_setnodevalue(EN_Project p, int index, int property, double valu
     double *Ucf = p->Ucf;
 
     int i, j, n;
-    Pdemand demand;
     Psource source;
     double hTmp;
 
@@ -2288,26 +2277,24 @@ int DLLEXPORT EN_setnodevalue(EN_Project p, int index, int property, double valu
         break;
 
     case EN_BASEDEMAND:
-        // NOTE: primary demand category is last on demand list
+        // NOTE: primary demand category is first on demand list
         if (index <= nJuncs)
         {
-            for (demand = Node[index].D; demand != NULL; demand = demand->next)
-            {
-                if (demand->next == NULL) demand->Base = value / Ucf[FLOW];
-            }
+            list_t *demand = Node[index].D;
+            if (demand)
+                set_base_demand(head_list(demand, false), value / Ucf[FLOW]);
         }
         break;
 
     case EN_PATTERN:
-        // NOTE: primary demand category is last on demand list
+        // NOTE: primary demand category is first on demand list
         j = ROUND(value);
         if (j < 0 || j > nPats) return 205;
         if (index <= nJuncs)
         {
-            for (demand = Node[index].D; demand != NULL; demand = demand->next)
-            {
-                if (demand->next == NULL) demand->Pat = j;
-            }
+            list_t *demand = Node[index].D;
+            if (demand)
+                set_pattern_index(head_list(demand, false), j);
         }
         else Tank[index - nJuncs].Pat = j;
         break;
@@ -2504,7 +2491,6 @@ int DLLEXPORT EN_setjuncdata(EN_Project p, int index, double elev,
 
     int i, patIndex = 0;
     Snode *Node = net->Node;
-    Pdemand demand;
 
     // Check that junction exists
     if (!p->Openflag) return 102;
@@ -2526,14 +2512,56 @@ int DLLEXPORT EN_setjuncdata(EN_Project p, int index, double elev,
 
     // Assign values to junction's parameters
     Node[index].El = elev / p->Ucf[ELEV];
-    for (demand = Node[index].D; demand != NULL; demand = demand->next)
-    {
-        if (demand->next == NULL)
-        {
-            demand->Base = dmnd / p->Ucf[FLOW];
-            demand->Pat = patIndex;
-        }
+
+    list_t *demand_list = Node[index].D;
+    if (!demand_list) {
+        demand_list = create_list(get_demand_data_size(), delete_demand_data);
+        if (!demand_list) return 101;
     }
+    demand_data_t *demand_data = create_demand_data(dmnd/p->Ucf[FLOW], patIndex, NULL);
+    if (!demand_data) return 101;
+
+    append_list(demand_list, &demand_data);
+
+    return 0;
+}
+
+int DLLEXPORT EN_adddemand(EN_Project p, int node_index, double demand,
+    char *demand_pattern, const char *category_name, int *demand_key)
+{
+    Network *net = &p->network;
+
+    int pattern_index, error = 0;
+    *demand_key = -1;
+
+    if (error = EN_getpatternindex(p, demand_pattern, &pattern_index) != 0) return error;
+
+    Snode *Node = net->Node;
+    list_t *demand_list = Node[node_index].D;
+    if (!demand_list) {
+        demand_list = create_demand_list(demand/p->Ucf[FLOW], pattern_index, category_name);
+        if (!demand_list) return 101;
+
+        Node[node_index].D = demand_list;
+    }
+    else {
+        demand_data_t *demand_data = create_demand_data(demand/p->Ucf[FLOW], pattern_index, category_name);
+        if (!demand_data) return 101;
+
+        *demand_key = append_list(demand_list, &demand_data);
+    }
+    return 0;
+}
+
+int DLLEXPORT EN_removedemand(EN_Project p, int node_index, int demand_key)
+{
+    Network *net = &p->network;
+    Snode *Node = net->Node;
+
+    list_t *dlist = Node[node_index].D;
+
+    remove_node(dlist, demand_key);
+
     return 0;
 }
 
@@ -2714,16 +2742,20 @@ int DLLEXPORT EN_getnumdemands(EN_Project p, int nodeIndex, int *numDemands)
 **----------------------------------------------------------------
 */
 {
-    Pdemand d;
-    int n = 0;
+    //Pdemand d;
+    //int n = 0;
 
     // Check for valid arguments
     if (!p->Openflag) return 102;
     if (nodeIndex <= 0 || nodeIndex > p->network.Nnodes) return 203;
 
     // Count the number of demand categories
-    for (d = p->network.Node[nodeIndex].D; d != NULL; d = d->next) n++;
-    *numDemands = n;
+	list_t *demand_list = p->network.Node[nodeIndex].D;
+	if (demand_list)
+		*numDemands = size_list(demand_list);
+	else
+		*numDemands = 0;
+
     return 0;
 }
 
@@ -2738,9 +2770,6 @@ int DLLEXPORT EN_getbasedemand(EN_Project p, int nodeIndex, int demandIndex,
 **----------------------------------------------------------------
 */
 {
-    Pdemand d;
-    int n = 1;
-
     // Check for valid arguments
     if (!p->Openflag) return 102;
     if (nodeIndex <= 0 || nodeIndex > p->network.Nnodes) return 203;
@@ -2748,10 +2777,13 @@ int DLLEXPORT EN_getbasedemand(EN_Project p, int nodeIndex, int demandIndex,
     // Retrieve demand for specified category
     if (nodeIndex <= p->network.Njuncs)
     {
-        for (d = p->network.Node[nodeIndex].D; n < demandIndex && d->next != NULL;
-             d = d->next) n++;
-        if (n != demandIndex) return 253;
-        *baseDemand = (double)(d->Base * p->Ucf[FLOW]);
+        // Locate demand category record and assign demandName to it
+        list_t *dlist = p->network.Node[nodeIndex].D;
+        list_node_t *lnode = get_nth_list(dlist, demandIndex);
+        if (!lnode)
+            return 253;
+        else
+            *baseDemand = get_base_demand(lnode) * p->Ucf[FLOW];
     }
     else *baseDemand = (double)(0.0);
     return 0;
@@ -2769,9 +2801,6 @@ int DLLEXPORT EN_setbasedemand(EN_Project p, int nodeIndex, int demandIndex,
 **----------------------------------------------------------------
 */
 {
-    Pdemand d;
-    int n = 1;
-
     // Check for valid arguments
     if (!p->Openflag) return 102;
     if (nodeIndex <= 0 || nodeIndex > p->network.Nnodes) return 203;
@@ -2779,10 +2808,22 @@ int DLLEXPORT EN_setbasedemand(EN_Project p, int nodeIndex, int demandIndex,
     // Set baseline demand for specified category
     if (nodeIndex <= p->network.Njuncs)
     {
-        for (d = p->network.Node[nodeIndex].D; n < demandIndex && d->next != NULL;
-             d = d->next) n++;
-        if (n != demandIndex) return 253;
-        d->Base = baseDemand / p->Ucf[FLOW];
+        list_t *dlist = p->network.Node[nodeIndex].D;
+        // If demand list is null create one and set demand
+        if (!dlist) {
+            dlist = create_demand_list(baseDemand / p->Ucf[FLOW], 0, NULL);
+            if (!dlist) return 101;
+
+            p->network.Node[nodeIndex].D = dlist;
+        }
+        // else find the demand entry and set demand
+        else {
+            list_node_t *lnode = get_nth_list(dlist, demandIndex);
+            if (!lnode)
+                return 253;
+            else
+            set_base_demand(lnode, baseDemand / p->Ucf[FLOW]);
+        }
     }
     return 0;
 }
@@ -2798,8 +2839,7 @@ int DLLEXPORT EN_getdemandname(EN_Project p, int nodeIndex, int demandIndex,
 **----------------------------------------------------------------
 */
 {
-    Pdemand d;
-    int n = 1;
+    char *temp = NULL;
 
     strcpy(demandName, "");
 
@@ -2808,12 +2848,21 @@ int DLLEXPORT EN_getdemandname(EN_Project p, int nodeIndex, int demandIndex,
     if (nodeIndex <= 0 || nodeIndex > p->network.Njuncs) return 203;
 
     // Locate demand category record and retrieve its name
-    for (d = p->network.Node[nodeIndex].D;
-        n < demandIndex && d->next != NULL; d = d->next) n++;
-    if (n != demandIndex) return 253;
+    list_t *dlist = p->network.Node[nodeIndex].D;
+    if (dlist) {
+        list_node_t *lnode = get_nth_list(dlist, demandIndex);
+        if (!lnode)
+            return 253;
+        else
+            temp = get_category_name(lnode);
+
+        if (temp) {
+            strcpy(demandName, temp);
+            free(temp);
+        }
+    }
+    else return 253;
 
-    if (d->Name) strcpy(demandName, d->Name);
-    else demandName[0] = '\0';
     return 0;
 }
 
@@ -2829,8 +2878,6 @@ int DLLEXPORT EN_setdemandname(EN_Project p, int nodeIndex, int demandIndex,
 **----------------------------------------------------------------
 */
 {
-    Pdemand d;
-    int n = 1;
 
     // Check for valid arguments
     if (!p->Openflag) return 102;
@@ -2840,10 +2887,20 @@ int DLLEXPORT EN_setdemandname(EN_Project p, int nodeIndex, int demandIndex,
     if (strlen(demandName) > MAXID) return 252;
 
     // Locate demand category record and assign demandName to it
-    for (d = p->network.Node[nodeIndex].D;
-         n < demandIndex && d->next != NULL; d = d->next) n++;
-    if (n != demandIndex) return 253;
-    d->Name = xstrcpy(&d->Name, demandName, MAXID);
+    list_t *dlist = p->network.Node[nodeIndex].D;
+    if (!dlist) {
+        dlist = create_demand_list(0, 0, demandName);
+        if (!dlist) return 101;
+
+        p->network.Node[nodeIndex].D = dlist;
+    }
+    else {
+        list_node_t *lnode = get_nth_list(dlist, demandIndex);
+        if (!lnode)
+            return 253;
+        else
+            set_category_name(lnode, demandName);
+    }
     return 0;
 }
 
@@ -2859,16 +2916,18 @@ int DLLEXPORT EN_getdemandpattern(EN_Project p, int nodeIndex, int demandIndex,
 **----------------------------------------------------------------
 */
 {
-    Pdemand d;
-    int n = 1;
-
     // Check for valid arguments
     if (!p->Openflag) return 102;
     if (nodeIndex <= 0 || nodeIndex > p->network.Nnodes) return 203;
-    for (d = p->network.Node[nodeIndex].D;
-         n < demandIndex && d->next != NULL; d = d->next) n++;
-    if (n != demandIndex) return 253;
-    *patIndex = d->Pat;
+
+    // Locate demand category record and assign demandName to it
+    list_t *dlist = p->network.Node[nodeIndex].D;
+    list_node_t *lnode = get_nth_list(dlist, demandIndex);
+    if (!lnode)
+        return 253;
+    else
+        *patIndex = get_pattern_index(lnode);
+
     return 0;
 }
 
@@ -2886,21 +2945,28 @@ int  DLLEXPORT EN_setdemandpattern(EN_Project p, int nodeIndex, int demandIndex,
 {
     Network *net = &p->network;
 
-    Pdemand d;
-    int n = 1;
-
     // Check for valid arguments
     if (!p->Openflag) return 102;
     if (nodeIndex <= 0 || nodeIndex > net->Nnodes) return 203;
     if (patIndex <= 0 || patIndex > net->Npats) return 205;
 
     // Locate demand category record and assign time pattern to it
-    if (nodeIndex <= net->Njuncs)
-    {
-        for (d = net->Node[nodeIndex].D;
-             n < demandIndex && d->next != NULL; d = d->next) n++;
-        if (n != demandIndex) return 253;
-        d->Pat = patIndex;
+    if (nodeIndex <= net->Njuncs) {
+
+        list_t *dlist = p->network.Node[nodeIndex].D;
+        if (!dlist) {
+            dlist = create_demand_list(0, patIndex, NULL);
+            if (!dlist) return 101;
+
+            p->network.Node[nodeIndex].D = dlist;
+        }
+        else {
+            list_node_t *lnode = get_nth_list(dlist, demandIndex);
+            if (!lnode)
+                return 253;
+            else
+                set_pattern_index(lnode, patIndex);
+        }
     }
     return 0;
 }
@@ -4338,7 +4404,7 @@ int DLLEXPORT EN_setcurveid(EN_Project p, int index, char *id)
 
     // Check if id name contains invalid characters
     if (!namevalid(id)) return 252;
-    
+
     for (i = 1; i <= p->network.Ncurves; i++)
     {
         if (i != index && strcmp(id, p->network.Curve[i].ID) == 0) return 215;
diff --git a/src/hydraul.c b/src/hydraul.c
index 1e3532e..515be11 100755
--- a/src/hydraul.c
+++ b/src/hydraul.c
@@ -27,6 +27,9 @@
 #include "funcs.h"
 #include "text.h"
 
+#include "demand.h"
+
+
 const double QZERO = 1.e-6;  // Equivalent to zero flow in cfs
 
 // Imported functions
@@ -553,7 +556,7 @@ void  demands(Project *pr)
     int  i ,j, n;
     long k, p;
     double djunc, sum;
-    Pdemand demand;
+//    Pdemand demand;
 
     // Determine total elapsed number of pattern periods
     p = (time->Htime + time->Pstart) / time->Pstep;
@@ -563,15 +566,19 @@ void  demands(Project *pr)
     for (i = 1; i <= net->Njuncs; i++)
     {
         sum = 0.0;
-        for (demand = net->Node[i].D; demand != NULL; demand = demand->next)
-        {
-            // pattern period (k) = (elapsed periods) modulus (periods per pattern)
-            j = demand->Pat;
-            k = p % (long) net->Pattern[j].Length;
-            djunc = (demand->Base) * net->Pattern[j].F[k] * hyd->Dmult;
-            if (djunc > 0.0) hyd->Dsystem += djunc;
-            sum += djunc;
-        }
+		list_t *dlist = net->Node[i].D;
+		
+		if (dlist) {
+			for (list_node_t *lnode = first_list(dlist); done_list(lnode); lnode = next_list(lnode))
+			{
+				// pattern period (k) = (elapsed periods) modulus (periods per pattern)
+				j = get_pattern_index(lnode);
+				k = p % (long)net->Pattern[j].Length;
+				djunc = (get_base_demand(lnode)) * net->Pattern[j].F[k] * hyd->Dmult;
+				if (djunc > 0.0) hyd->Dsystem += djunc;
+				sum += djunc;
+			}
+		}
         hyd->NodeDemand[i] = sum;
 
         // Initialize pressure dependent demand
diff --git a/src/inpfile.c b/src/inpfile.c
index 946f364..be24616 100644
--- a/src/inpfile.c
+++ b/src/inpfile.c
@@ -28,6 +28,8 @@ Last Updated: 04/03/2019
 #include "hash.h"
 #include "text.h"
 
+#include "demand.h"
+
 // Defined in enumstxt.h in EPANET.C
 extern char *LinkTxt[];
 extern char *FormTxt[];
@@ -119,6 +121,48 @@ void saveauxdata(Project *pr, FILE *f)
     InFile = NULL;
 }
 
+
+void write_demands(Project *pr, FILE *f) {
+    int i, j;
+
+    Snode *node = NULL;
+    list_node_t *lnode = NULL;
+    char *temp = NULL;
+
+    char  s[MAXLINE + 1],
+    s1[MAXLINE + 1];
+
+    double ucf = pr->Ucf[DEMAND];
+    Network *net = &pr->network;
+
+    fprintf(f, "\n\n");
+    fprintf(f, s_DEMANDS);
+
+    for (i = 1; i <= net->Njuncs; i++) {
+        node = &net->Node[i];
+        if (node->D) {
+            for (lnode = first_list(node->D); done_list(lnode); lnode = next_list(lnode)) {
+                if (lnode) {
+                    sprintf(s, " %-31s %14.6f", node->ID, ucf * get_base_demand(lnode));
+
+                    if
+                        ((j = get_pattern_index(lnode)) > 0) sprintf(s1, " %-31s", net->Pattern[j].ID);
+                    else
+                        strcpy(s1, " ");
+
+                    fprintf(f, "\n%s %-31s", s, s1);
+
+                    if (temp = get_category_name(lnode)) {
+                        fprintf(f, " ;%s", temp);
+                        free(temp);
+                    }
+                }
+            }
+        }
+    }
+}
+
+
 int saveinpfile(Project *pr, const char *fname)
 /*
 -------------------------------------------------
@@ -135,9 +179,9 @@ int saveinpfile(Project *pr, const char *fname)
     Times   *time = &pr->times;
 
     int i, j, n;
-    double d, kc, ke, km, ucf;
+    double d, kc, ke, km;
     char s[MAXLINE + 1], s1[MAXLINE + 1], s2[MAXLINE + 1];
-    Pdemand demand;
+    //Pdemand demand;
     Psource source;
     FILE *f;
     Slink *link;
@@ -325,22 +369,10 @@ int saveinpfile(Project *pr, const char *fname)
         if (link->Comment) fprintf(f, " ;%s", link->Comment);
     }
 
+
     // Write [DEMANDS] section
-    fprintf(f, "\n\n");
-    fprintf(f, s_DEMANDS);
-    ucf = pr->Ucf[DEMAND];
-    for (i = 1; i <= net->Njuncs; i++)
-    {
-        node = &net->Node[i];
-        for (demand = node->D; demand != NULL; demand = demand->next)
-        {
-            sprintf(s, " %-31s %14.6f", node->ID, ucf * demand->Base);
-            if ((j = demand->Pat) > 0) sprintf(s1, " %-31s", net->Pattern[j].ID);
-            else strcpy(s1, " ");
-            fprintf(f, "\n%s %-31s", s, s1);
-            if (demand->Name) fprintf(f, " ;%s", demand->Name);
-        }
-    }
+    write_demands(pr, f);
+
 
     // Write [EMITTERS] section
     fprintf(f, "\n\n");
diff --git a/src/input1.c b/src/input1.c
index 219caaf..391fc69 100644
--- a/src/input1.c
+++ b/src/input1.c
@@ -23,6 +23,8 @@ Last Updated: 04/03/2019
 
 #include <math.h>
 
+#include "demand.h"
+
 #include "types.h"
 #include "funcs.h"
 #include "hash.h"
@@ -220,9 +222,9 @@ void adjustdata(Project *pr)
 
     int i;
     double ucf;     // Unit conversion factor
-    Pdemand demand; // Pointer to demand record
+    //Pdemand demand; // Pointer to demand record
     Slink *link;
-    Snode *node;
+    //Snode *node;
     Stank *tank;
 
     // Use 1 hr pattern & report time step if none specified
@@ -329,17 +331,17 @@ void adjustdata(Project *pr)
         tank = &net->Tank[i];
         if (tank->Kb == MISSING) tank->Kb = qual->Kbulk;
     }
-
-    // Use default pattern if none assigned to a demand
-    parser->DefPat = findpattern(net, parser->DefPatID);
-    if (parser->DefPat > 0) for (i = 1; i <= net->Nnodes; i++)
-    {
-        node = &net->Node[i];
-        for (demand = node->D; demand != NULL; demand = demand->next)
-        {
-            if (demand->Pat == 0) demand->Pat = parser->DefPat;
-        }
-    }
+ 
+	// Use default pattern if none assigned to a demand
+	parser->DefPat = findpattern(net, parser->DefPatID);
+	if (parser->DefPat > 0) {
+		for (i = 1; i <= net->Nnodes; i++) {
+			for (list_node_t *lnode = first_list((&net->Node[i])->D); done_list(lnode); lnode = next_list(lnode)) {
+				if (get_pattern_index(lnode) == 0)
+					set_pattern_index(lnode, parser->DefPat);
+			}
+		}
+	}
 
     // Remove QUALITY as a reporting variable if no WQ analysis
     if (qual->Qualflag == NONE) rpt->Field[QUALITY].Enabled = FALSE;
@@ -542,7 +544,7 @@ void convertunits(Project *pr)
 
     int i, j, k;
     double ucf;     // Unit conversion factor
-    Pdemand demand; // Pointer to demand record
+    //Pdemand demand; // Pointer to demand record
     Snode *node;
     Stank *tank;
     Slink *link;
@@ -562,11 +564,17 @@ void convertunits(Project *pr)
     for (i = 1; i <= net->Njuncs; i++)
     {
         node = &net->Node[i];
-        for (demand = node->D; demand != NULL; demand = demand->next)
-        {
-            demand->Base /= pr->Ucf[DEMAND];
-        }
+		list_t *dlist = node->D;
+		if (dlist) {
+			for (list_node_t *lnode = first_list(dlist); done_list(lnode); lnode = next_list(lnode))
+				convert_units(lnode, pr->Ucf[DEMAND]);
+		}
+      //  for (demand = node->D; demand != NULL; demand = demand->next)
+      //  {
+      //      demand->Base /= pr->Ucf[DEMAND];
+      //  }
     }
+
     hyd->Pmin /= pr->Ucf[PRESSURE];
     hyd->Preq /= pr->Ucf[PRESSURE];
 
diff --git a/src/input3.c b/src/input3.c
index 61324a3..7951cdf 100644
--- a/src/input3.c
+++ b/src/input3.c
@@ -23,6 +23,7 @@ Last Updated: 04/03/2019
 
 #include <math.h>
 
+#include "demand.h"
 #include "types.h"
 #include "funcs.h"
 #include "hash.h"
@@ -80,12 +81,15 @@ int juncdata(Project *pr)
     Parser  *parser = &pr->parser;
     Hydraul *hyd = &pr->hydraul;
 
-    int p = 0;          // time pattern index
-    int n;              // number of tokens
-    int njuncs;         // number of network junction nodes
-    double el,          // elevation
-           y = 0.0;     // base demand
-    Pdemand demand;     // demand record
+    int p = 0;                  // time pattern index
+    int n;                      // number of tokens
+    int njuncs;                 // number of network junction nodes
+    double el,                  // elevation
+           y = 0.0;             // base demand
+    
+	list_t *demand_list = NULL; // demand list
+
+
     Snode *node;
 
     // Add new junction to data base
@@ -118,14 +122,13 @@ int juncdata(Project *pr)
     node->Type = JUNCTION;
     node->Comment = xstrcpy(&node->Comment, parser->Comment, MAXMSG);
 
-    // create a demand record, even if no demand is specified here.
-    demand = (struct Sdemand *) malloc(sizeof(struct Sdemand));
-    if (demand == NULL) return 101;
-    demand->Base = y;
-    demand->Pat = p;
-    demand->Name = NULL;
-    demand->next = NULL;
-    node->D = demand;
+	// create demand data only if a demand has been specified
+	if (y != 0.0) {
+		demand_list = create_demand_list(y, p, NULL);
+		if (!demand_list) return 101;
+	}
+    node->D = demand_list;
+
     hyd->NodeDemand[njuncs] = y;
     return 0;
 }
@@ -709,8 +712,12 @@ int demanddata(Project *pr)
 
     int j, n, p = 0;
     double y;
-    Pdemand demand;
-    Pdemand cur_demand;
+
+	list_t *demand_list = NULL;
+	demand_data_t *demand_data = NULL;
+    
+	//Pdemand demand;
+    //Pdemand cur_demand;
 
     // Extract data from tokens
     n = parser->Ntokens;
@@ -734,38 +741,27 @@ int demanddata(Project *pr)
         if (p == 0) return setError(parser, 2, 205);
     }
 
-    // Replace any demand entered in [JUNCTIONS] section
-    demand = net->Node[j].D;
-    if (hyd->NodeDemand[j] != MISSING)
-    {
-        // First category encountered will overwrite "dummy" demand category
-        // with what is specified in this section
-        demand->Base = y;
-        demand->Pat = p;
-        if (parser->Comment[0])
-        {
-            demand->Name = xstrcpy(&demand->Name, parser->Comment, MAXID);
-        }
-        hyd->NodeDemand[j] = MISSING; // marker - next iteration will append a new category.
-    }
+   
+	// if no demands were specified in [JUNCTIONS] create the list here 
+	demand_list = net->Node[j].D;
+	if (demand_list == NULL) {
+		demand_list = create_list(get_demand_data_size(), delete_demand_data);
+		if (demand_list == NULL) return 101;
+		net->Node[j].D = demand_list;
+	}
+	
+	// else replace the demand data entered in [JUNCTIONS] section
+	else if (size_list(demand_list) == 1) {
+		list_node_t *lnode = head_list(demand_list, true);
+		delete_node(demand_list, lnode);
+	}
+
+	// append the data to the list
+	demand_data = create_demand_data(y, p, parser->Comment);
+	if (demand_data == NULL) return 101;
+
+	append_list(demand_list, &demand_data);
 
-    // Otherwise add new demand to junction
-    else
-    {
-        cur_demand = net->Node[j].D;
-        while (cur_demand->next != NULL) cur_demand = cur_demand->next;
-        demand = (struct Sdemand *)malloc(sizeof(struct Sdemand));
-        if (demand == NULL) return 101;
-        demand->Base = y;
-        demand->Pat = p;
-        demand->Name = NULL;
-        if (parser->Comment[0])
-        {
-            demand->Name = xstrcpy(&demand->Name, parser->Comment, MAXID);
-        }
-        demand->next = NULL;
-        cur_demand->next = demand;
-    }
     return 0;
 }
 
diff --git a/src/project.c b/src/project.c
index f98be65..49696a3 100644
--- a/src/project.c
+++ b/src/project.c
@@ -29,6 +29,8 @@
 #include "types.h"
 #include "funcs.h"
 
+#include "demand.h"
+
 int openfiles(Project *pr, const char *f1, const char *f2, const char *f3)
 /*----------------------------------------------------------------
 **  Input:   f1 = pointer to name of input file
@@ -385,7 +387,7 @@ void freedata(Project *pr)
 */
 {
     int j;
-    Pdemand demand, nextdemand;
+    //Pdemand demand, nextdemand;
 
     // Free memory for computed results
     free(pr->hydraul.NodeDemand);
@@ -404,14 +406,10 @@ void freedata(Project *pr)
         for (j = 1; j <= pr->parser.MaxNodes; j++)
         {
             // Free memory used for demand category list
-            demand = pr->network.Node[j].D;
-            while (demand != NULL)
-            {
-                nextdemand = demand->next;
-                free(demand->Name);
-                free(demand);
-                demand = nextdemand;
-            }
+			list_t *demand = pr->network.Node[j].D;
+			if(demand)
+				delete_list(demand);
+
             // Free memory used for WQ source data
             free(pr->network.Node[j].S);
             free(pr->network.Node[j].Comment);
@@ -788,10 +786,20 @@ void adjustpattern(int *pat, int index)
 **----------------------------------------------------------------
 */
 {
-    if (*pat == index) *pat = 0;
-    else if (*pat > index) (*pat)--;
+	if (*pat == index) *pat = 0;
+	else if (*pat > index) (*pat)--;
 }
 
+
+void adjust_demand_pattern(list_node_t *list_node, int deletion_index)
+{
+	int pat_idx = get_pattern_index(list_node);
+
+	if (pat_idx == deletion_index) set_pattern_index(list_node, 0);
+	else if (pat_idx > deletion_index) set_pattern_index(list_node, --pat_idx);
+}
+
+
 void adjustpatterns(Network *network, int index)
 /*----------------------------------------------------------------
 **  Input:   index = index of time pattern being deleted
@@ -801,16 +809,17 @@ void adjustpatterns(Network *network, int index)
 */
 {
     int j;
-    Pdemand demand;
+    //Pdemand demand;
     Psource source;
 
     // Adjust patterns used by junctions
     for (j = 1; j <= network->Nnodes; j++)
     {
         // Adjust demand patterns
-        for (demand = network->Node[j].D; demand != NULL; demand = demand->next)
-        {
-            adjustpattern(&demand->Pat, index);
+        list_t *dlist = network->Node[j].D;
+        if (dlist) {
+            for (list_node_t *lnode = first_list(dlist); done_list(lnode); lnode = next_list(lnode))
+                adjust_demand_pattern(lnode, index);
         }
         // Adjust WQ source patterns
         source = network->Node[j].S;
diff --git a/src/types.h b/src/types.h
index 476afac..b848238 100755
--- a/src/types.h
+++ b/src/types.h
@@ -14,15 +14,18 @@
 #ifndef TYPES_H
 #define TYPES_H
 
-#include "hash.h"
 #include <stdio.h>
 
+
+#include "hash.h"
+#include "util/list.h"
+
 /*
 -------------------------------------------
    Definition of 4-byte integers & reals
 -------------------------------------------
 */
-typedef  float        REAL4;                                                   
+typedef  float        REAL4;
 typedef  int          INT4;
 
 /*
@@ -64,7 +67,7 @@ typedef  int          INT4;
    Flow units conversion factors
 ----------------------------------------------
 */
-#define   GPMperCFS   448.831 
+#define   GPMperCFS   448.831
 #define   AFDperCFS   1.9837
 #define   MGDperCFS   0.64632
 #define   IMGDperCFS  0.5382
@@ -91,9 +94,9 @@ typedef  int          INT4;
 
 /*
 ---------------------------------------------------------------------
-   Conversion macros to be used in place of functions             
+   Conversion macros to be used in place of functions
 ---------------------------------------------------------------------
-*/ 
+*/
 #define INT(x)   ((int)(x))                   // integer portion of x
 #define FRAC(x)  ((x)-(int)(x))               // fractional part of x
 #define ABS(x)   (((x)<0) ? -(x) : (x))       // absolute value of x
@@ -109,10 +112,10 @@ typedef  int          INT4;
 /*
 ------------------------------------------------------
    Macro to evaluate function x with error checking
-   (Fatal errors are numbered higher than 100)             
+   (Fatal errors are numbered higher than 100)
 ------------------------------------------------------
 */
-#define ERRCODE(x) (errcode = ((errcode>100) ? (errcode) : (x))) 
+#define ERRCODE(x) (errcode = ((errcode>100) ? (errcode) : (x)))
 
 /*
 ----------------------------------------------
@@ -187,7 +190,7 @@ typedef enum {
   HILEVEL,       // act when grade above set level
   TIMER,         // act when set time reached
   TIMEOFDAY      // act when time of day occurs
-} ControlType;    
+} ControlType;
 
 typedef enum {
   XHEAD,         // pump cannot deliver head (closed)
@@ -206,12 +209,12 @@ typedef enum {
   HW,            // Hazen-Williams
   DW,            // Darcy-Weisbach
   CM             // Chezy-Manning
-} HeadLossType;    
+} HeadLossType;
 
 typedef enum {
   US,            // US
   SI             // SI (metric)
-} UnitsType;          
+} UnitsType;
 
 typedef enum {
   CFS,           // cubic feet per second
@@ -224,7 +227,7 @@ typedef enum {
   MLD,           // megaliters per day
   CMH,           // cubic meters per hour
   CMD            // cubic meters per day
-} FlowUnitsType;         
+} FlowUnitsType;
 
 typedef enum {
   PSI,           // pounds per square inch
@@ -236,14 +239,14 @@ typedef enum {
   LOW,           // lower limit
   HI,            // upper limit
   PREC           // precision
-} RangeType;        
+} RangeType;
 
 typedef enum {
   MIX1,          // complete mix model
   MIX2,          // 2-compartment model
   FIFO,          // first in, first out model
   LIFO           // last in, first out model
-} MixType;       
+} MixType;
 
 typedef enum {
   SERIES,        // point time series
@@ -259,7 +262,7 @@ typedef enum {
   HEAD,          // nodal hydraulic head
   PRESSURE,      // nodal pressure
   QUALITY,       // nodal water quality
-  
+
   LENGTH,        // link length
   DIAM,          // link diameter
   FLOW,          // link flow rate
@@ -270,7 +273,7 @@ typedef enum {
   SETTING,       // pump/valve setting
   REACTRATE,     // avg. reaction rate in link
   FRICTION,      // link friction factor
-  
+
   POWER,         // pump power output
   TIME,          // simulation time
   VOLUME,        // tank volume
@@ -293,7 +296,7 @@ typedef enum {
   ENERHDR,       // energy usage header
   NODEHDR,       // node results header
   LINKHDR        // link results header
-} HdrType;    
+} HdrType;
 
 typedef enum {
   NEGATIVE  = -1,  // flow in reverse of pre-assigned direction
@@ -302,13 +305,13 @@ typedef enum {
 } FlowDirection;
 
 typedef enum {
-  DDA,           // demand driven analysis    
+  DDA,           // demand driven analysis
   PDA            // pressure driven analysis
 } DemandModelType;
 
 /*
 ------------------------------------------------------
-   Fundamental Data Structures                             
+   Fundamental Data Structures
 ------------------------------------------------------
 */
 
@@ -336,14 +339,14 @@ typedef struct             // Curve Object
   double    *Y;            // y-values
 } Scurve;
 
-struct Sdemand             // Demand List Item
-{
-  double Base;             // baseline demand
-  int    Pat;              // pattern index
-  char   *Name;            // demand category name
-  struct Sdemand *next;    // next demand list item
-};
-typedef struct Sdemand *Pdemand; // Pointer to demand list
+//struct Sdemand             // Demand List Item
+//{
+//  double Base;             // baseline demand
+//  int    Pat;              // pattern index
+//  char   *Name;            // demand category name
+//  struct Sdemand *next;    // next demand list item
+//};
+//typedef struct Sdemand *Pdemand; // Pointer to demand list
 
 typedef struct             // Energy Usage Object
 {
@@ -370,7 +373,8 @@ typedef struct             // Node Object
   double   X;              // x-coordinate
   double   Y;              // y-coordinate
   double   El;             // elevation
-  Pdemand  D;              // demand pointer
+//  Pdemand  D;              // demand pointer
+  list_t   *D;             // pointer to demand list
   Psource  S;              // source pointer
   double   C0;             // initial quality
   double   Ke;             // emitter coeff.
@@ -383,7 +387,7 @@ typedef struct             // Link Object
 {
   char     ID[MAXID+1];    // link ID
   int      N1;             // start node index
-  int      N2;             // end node index 
+  int      N2;             // end node index
   double   Diam;           // diameter
   double   Len;            // length
   double   Kc;             // roughness
@@ -510,7 +514,7 @@ typedef struct s_ActionItem    // Action List Item
 {
     int     ruleIndex;           // index of rule action belongs to
     Saction *action;             // an action clause
-    struct  s_ActionItem *next;  // next action on the list   
+    struct  s_ActionItem *next;  // next action on the list
 } SactionList;
 
 typedef struct                 // Mass Balance Components
@@ -532,15 +536,15 @@ typedef struct                 // Mass Balance Components
 // Input File Parser Wrapper
 typedef struct {
   FILE *InFile;            // Input file handle
-  
+
   char
       DefPatID[MAXID + 1],     // Default demand pattern ID
       InpFname[MAXFNAME + 1],  // Input file name
       *Tok[MAXTOKS],           // Array of token strings
       Comment[MAXMSG + 1],     // Comment text
       LineComment[MAXMSG + 1]; // Full line comment
-  
-  int      
+
+  int
     MaxNodes,              // Node count   from input file */
     MaxLinks,              // Link count    "    "    "
     MaxJuncs,              // Junction count "   "    "
@@ -559,7 +563,7 @@ typedef struct {
     Flowflag,              // Flow units flag
     Pressflag,             // Pressure units flag
     DefPat;                // Default demand pattern
-  
+
   Spattern *PrevPat;       // Previous pattern processed
   Scurve   *PrevCurve;     // Previous curve processed
   double *X;               // Temporary array for curve data
@@ -590,7 +594,7 @@ typedef struct {
 typedef struct {
 
   FILE *RptFile;           // Report file handle
-  
+
   int
     Nperiods,              // Number of reporting periods
     PageSize,              // Lines/page in output report/
@@ -607,13 +611,13 @@ typedef struct {
   long
     LineNum,               // Current line number
     PageNum;               // Current page number
-  
+
   char
     Atime[13],             // Clock time (hrs:min:sec)
     Rpt1Fname[MAXFNAME+1], // Primary report file name
     Rpt2Fname[MAXFNAME+1], // Secondary report file name
     DateStamp[26];         // Current date & time
-  
+
   SField   Field[MAXVAR];  // Output reporting fields
 
 } Report;
@@ -624,19 +628,19 @@ typedef struct {
   char
     HydFname[MAXFNAME+1],  // Hydraulics file name
     OutFname[MAXFNAME+1];  // Binary output file name
-    
+
   int
     Outflag,               // Output file flag
     Hydflag,               // Hydraulics flag
     SaveHflag,             // Hydraulic results saved flag
     SaveQflag,             // Quality results saved flag
     Saveflag;              // General purpose save flag
-  
-  long     
+
+  long
     HydOffset,             // Hydraulics file byte offset
     OutOffset1,            // 1st output file byte offset
     OutOffset2;            // 2nd output file byte offset
-  
+
   FILE
     *OutFile,              // Output file handle
     *HydFile,              // Hydraulics file handle
@@ -665,7 +669,7 @@ typedef struct {
     *Aij,        // Non-zero, off-diagonal matrix coeffs.
     *F,          // Right hand side vector
     *temp;       // Array used by linear eqn. solver
-  
+
   int
     Ncoeffs,     // Number of non-zero matrix coeffs
     *Order,      // Node-to-row of re-ordered matrix
@@ -683,7 +687,7 @@ typedef struct {
 // Hydraulics Solver Wrapper
 typedef struct {
 
-  double  
+  double
     *NodeHead,             // Node hydraulic heads
     *NodeDemand,           // Node demand + emitter flows
     *DemandFlow,           // Demand outflows
@@ -711,13 +715,13 @@ typedef struct {
     Dcost,                 // Energy demand charge/kw/day
     Emax,                  // Peak energy usage
     RelativeError,         // Total flow change / total flow
-    MaxHeadError,          // Max. error for link head loss 
+    MaxHeadError,          // Max. error for link head loss
     MaxFlowChange,         // Max. change in link flow
     RelaxFactor,           // Relaxation factor for flow updating
     *P,                    // Inverse of head loss derivatives
     *Y,                    // Flow correction factors
     *Xflow;                // Inflow - outflow at each node
-  
+
   int
     Epat,                  // Energy cost time pattern
     DemandModel,           // Fixed or pressure dependent
@@ -730,10 +734,10 @@ typedef struct {
     OpenHflag,             // Hydraulic system opened flag
     Haltflag;              // Flag to halt simulation
 
-  StatusType  
+  StatusType
     *LinkStatus,           // Link status
     *OldStatus;            // Previous link/tank status
-  
+
   Smatrix smatrix;         // Sparse matrix storage
 
 } Hydraul;
@@ -747,7 +751,7 @@ typedef struct {
   int
     Qualflag,              // Water quality analysis flag
     OpenQflag,             // Quality system opened flag
-    Reactflag,             // Reaction indicator 
+    Reactflag,             // Reaction indicator
     OutOfMemory,           // Out of memory indicator
     TraceNode,             // Source node for flow tracing
     *SortedNodes;          // Topologically sorted node indexes
@@ -768,17 +772,17 @@ typedef struct {
     Bucf,                  // Bulk reaction units conversion factor
     Tucf,                  // Tank reaction units conversion factor
     BulkOrder,             // Bulk flow reaction order
-    WallOrder,             // Pipe wall reaction order     
-    TankOrder,             // Tank reaction order          
-    Kbulk,                 // Global bulk reaction coeff.  
-    Kwall,                 // Global wall reaction coeff.  
+    WallOrder,             // Pipe wall reaction order
+    TankOrder,             // Tank reaction order
+    Kbulk,                 // Global bulk reaction coeff.
+    Kwall,                 // Global wall reaction coeff.
     Climit,                // Limiting potential quality
     SourceQual,            // External source quality
     *NodeQual,             // Reported node quality state
     *PipeRateCoeff;        // Pipe reaction rate coeffs.
 
   struct Mempool
-    *SegPool;              // Memory pool for water quality segments   
+    *SegPool;              // Memory pool for water quality segments
 
   Pseg
     FreeSeg,               // Pointer to unused segment
@@ -808,7 +812,7 @@ typedef struct {
     Nrules,                // Number of control rules
     Npats,                 // Number of time patterns
     Ncurves;               // Number of data curves
-  
+
   Snode    *Node;          // Node array
   Slink    *Link;          // Link array
   Stank    *Tank;          // Tank array
@@ -836,13 +840,13 @@ typedef struct Project {
   Rules      rules;              // Rule-based controls wrapper
   Hydraul    hydraul;            // Hydraulics solver wrapper
   Quality    quality;            // Water quality solver wrapper
-  
+
   double Ucf[MAXVAR];            // Unit conversion factors
-  
+
   int
     Openflag,                    // Project open flag
     Warnflag;                    // Warning flag
-    
+
   char
     Msg[MAXMSG+1],               // General-purpose string: errors, messages
     Title[MAXTITLE][TITLELEN+1], // Project title
@@ -850,9 +854,9 @@ typedef struct Project {
     TmpHydFname[MAXFNAME+1],     // Temporary hydraulics file name
     TmpOutFname[MAXFNAME+1],     // Temporary output file name
     TmpStatFname[MAXFNAME+1];    // Temporary statistic file name
-  
-  void (* viewprog) (char *);    // Pointer to progress viewing function   
-  
+
+  void (* viewprog) (char *);    // Pointer to progress viewing function
+
 } Project, *EN_Project;
 
 #endif
diff --git a/src/util/list.c b/src/util/list.c
index d3e41d8..443fcf2 100644
--- a/src/util/list.c
+++ b/src/util/list.c
@@ -22,6 +22,7 @@
 #endif
 
 #include <string.h>
+#include <time.h>
 #include <assert.h>
 
 #include "list.h"
@@ -29,6 +30,7 @@
 
 typedef struct list_node_s {
     void *data;
+    int key;
     struct list_node_s *next;
 } list_node_t;
 
@@ -42,6 +44,9 @@ typedef struct list_s {
 } list_t;
 
 
+// local declarations
+int gen_key();
+
 list_t *create_list(size_t elementSize, freeFunction freeFn)
 {
     list_t *list;
@@ -67,12 +72,14 @@ void delete_list(list_t *list)
     free(list);
 }
 
-void prepend_list(list_t *list, void *element)
+int prepend_list(list_t *list, void *element)
 {
     list_node_t *node = malloc(sizeof(list_node_t));
     node->data = malloc(list->elementSize);
     memcpy(node->data, element, list->elementSize);
 
+    node->key = gen_key();
+
     node->next = list->head;
     list->head = node;
 
@@ -82,14 +89,18 @@ void prepend_list(list_t *list, void *element)
     }
 
     list->logicalLength++;
+
+    return node->key;
 }
 
-void append_list(list_t *list, void *element)
+int append_list(list_t *list, void *element)
 {
 	list_node_t *node = malloc(sizeof(list_node_t));
     node->data = malloc(list->elementSize);
     node->next = NULL;
 
+    node->key = gen_key();
+
     memcpy(node->data, element, list->elementSize);
 
     if(list->logicalLength == 0) {
@@ -100,34 +111,37 @@ void append_list(list_t *list, void *element)
     }
 
     list->logicalLength++;
+
+    return node->key;
 }
 
+
 void for_each_list(list_t *list, listIterator iterator)
 {
     assert(iterator != NULL);
 
     list_node_t *node = list->head;
     bool result = true;
-    while(node != NULL && result) {
-        result = iterator(node);
+
+	while(node != NULL && result) {
+		result = iterator(node);
         node = node->next;
     }
 }
 
 list_node_t *head_list(list_t *list, bool removeFromList)
-//
 // Warning: When node is removed caller is responsible for freeing it.
-//
 {
-    assert(list->head != NULL);
-
-    list_node_t *node = list->head;
-    if(removeFromList) {
-        // Disconnecting head node
-        list->head = node->next;
-        list->logicalLength--;
+    if (list) {
+        list_node_t *node = list->head;
+        if (removeFromList) {
+            // Disconnecting head node
+            list->head = node->next;
+            list->logicalLength--;
+        }
+        return node;
     }
-    return node;
+    return NULL;
 }
 
 list_node_t *tail_list(list_t *list)
@@ -136,16 +150,83 @@ list_node_t *tail_list(list_t *list)
     return list->tail;
 }
 
+list_node_t *get_nth_list(list_t *list, int index)
+{
+    int n;
+    list_node_t *lnode;
+
+    for (n = 1, lnode = first_list(list); n < index && done_list(lnode); n++, lnode = next_list(lnode));
+    if (n != index)
+        return NULL;
+    else
+        return lnode;
+}
+
+list_node_t *search_list(list_t *list, int key)
+// Naive list search. Will not perform for large lists.
+{
+    list_node_t *lnode = first_list(list);
+
+    while (done_list(lnode)) {
+        if (get_key(lnode) == key)
+            return lnode;
+        lnode = next_list(lnode);
+    }
+    return NULL;
+}
+
+void remove_node(list_t *list, int key)
+{
+    list_node_t *temp;
+    list_node_t *target = search_list(list, key);
+
+    if (target == list->head)
+        delete_node(list, head_list(list, true));
+
+    else if (target == list->tail) {
+        // find next to last node
+        temp = list->head;
+        while (temp != NULL) {
+            if (temp->next == target)
+                break;
+            temp = temp->next;
+        }
+        // detatch tail
+        temp->next = NULL;
+        delete_node(list, list->tail);
+    }
+    else {
+        temp = target->next;
+        list->freeFn(target->data);
+        free(target->data);
+
+        target->data = temp->data;
+        target->next = temp->next;
+
+        free(temp);
+    }
+}
+
 int size_list(list_t *list)
 {
     return list->logicalLength;
 }
 
+int get_key(list_node_t *lnode)
+{
+    return lnode->key;
+}
+
 void *get_data(list_node_t *lnode)
 {
     return lnode->data;
 }
 
+list_node_t *get_next(list_node_t *lnode)
+{
+	return lnode->next;
+}
+
 void delete_node(list_t *list, list_node_t *lnode)
 {
     if (list->freeFn)
@@ -155,22 +236,11 @@ void delete_node(list_t *list, list_node_t *lnode)
     free(lnode);
 }
 
-//
-// Iterator first/done/next operations provide containment for list abstraction
-// http://www.cs.yale.edu/homes/aspnes/pinewiki/C(2f)Iterators.html
-// Accessed on April 11, 2019
-//
-list_node_t *first_list(list_t *list)
-{
-    return list->head;
-}
 
-bool done_list(list_node_t *lnode)
-{
-    return lnode != NULL;
-}
+// local functions
 
-list_node_t *next_list(list_node_t *lnode)
+int gen_key()
+// Naive key generator. No guarentee of uniqueness
 {
-    return lnode->next;
+    return rand();
 }
diff --git a/src/util/list.h b/src/util/list.h
index 090fa4a..599acde 100644
--- a/src/util/list.h
+++ b/src/util/list.h
@@ -19,6 +19,7 @@
 
 #include <stdbool.h>
 
+
 #if defined(__cplusplus)
 extern "C" {
 #endif
@@ -28,8 +29,8 @@ extern "C" {
 typedef struct list_node_s list_node_t;
 typedef struct list_s list_t;
 
-typedef void(*freeFunction)(void *);
-typedef bool(*listIterator)(list_node_t *);
+typedef void (*freeFunction) (void *);
+typedef bool (*listIterator) (list_node_t *);
 
 
 /**
@@ -45,14 +46,14 @@ with each node’s data pointer.
 void delete_list(list_t *list);
 
 /**
-@brief Adds a node to the head of the list.
+@brief Adds a node to the head of the list and returns its key.
 */
-void prepend_list(list_t *list, void *element);
+int prepend_list(list_t *list, void *element);
 
 /**
-@brief Adds a node to the tail of the list.
+@brief Adds a node to the tail of the list and returns its key.
 */
-void append_list(list_t *list, void *element);
+int append_list(list_t *list, void *element);
 
 /**
 @brief Returns the number of items in the list.
@@ -65,6 +66,16 @@ int size_list(list_t *list);
 */
 void *get_data(list_node_t *lnode);
 
+/**
+@brief Returns list node's key value.
+*/
+int get_key(list_node_t *lnode);
+
+/**
+@brief Returns next list node.
+*/
+list_node_t *get_next(list_node_t *lnode);
+
 /**
 @brief Frees memory associated with a list node.
 */
@@ -87,21 +98,41 @@ list_node_t *head_list(list_t *list, bool removeFromList);
 */
 list_node_t *tail_list(list_t *list);
 
+/**
+@brief Returns nth node of the list or NULL.
+*/
+list_node_t *get_nth_list(list_t *list, int index);
+
+/**
+@brief Returns the list node with the given key or NULL.
+*/
+list_node_t *search_list(list_t *list, int key);
+
+/**
+@brief Removes the list node with the given key from the list. 
+*/
+void remove_node(list_t *list, int key);
+
+//
+// Iterator first/done/next operations
+// http://www.cs.yale.edu/homes/aspnes/pinewiki/C(2f)Iterators.html
+// Accessed on April 11, 2019
+//
 
 /**
 @brief Returns list head node.
 */
-list_node_t *first_list(list_t *list);
+static inline list_node_t *first_list(list_t *list) { return head_list(list, false); }
 
 /**
 @brief Returns true if end of list false otherwise.
 */
-bool done_list(list_node_t *lnode);
+static inline bool done_list(list_node_t *lnode) { return lnode != NULL; }
 
 /**
 @brief Returns next node in the list.
 */
-list_node_t *next_list(list_node_t *lnode);
+static inline list_node_t *next_list(list_node_t *lnode) { return get_next(lnode); }
 
 
 #if defined(__cplusplus)
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 0a5f91e..62f6f00 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -23,6 +23,15 @@ add_test(NAME test_net_builder
     WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/data)
 
 
+add_executable(test_demand_data test_demand_data.cpp
+                                ../src/demand.c
+                                ../src/util/list.c)
+target_include_directories(test_demand_data PUBLIC ../src/ ../src/util/)
+target_link_libraries(test_demand_data ${Boost_LIBRARIES} epanet2)
+add_test(NAME test_demand_data
+    COMMAND ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/test_demand_data
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/data)
+
 
 set(toolkit_test_srcs
      test_toolkit.cpp
diff --git a/tests/test_demand.cpp b/tests/test_demand.cpp
index 9a02ff7..80bf042 100644
--- a/tests/test_demand.cpp
+++ b/tests/test_demand.cpp
@@ -18,6 +18,7 @@
 
 BOOST_AUTO_TEST_SUITE (test_demand)
 
+
 BOOST_AUTO_TEST_CASE(test_categories_save)
 {
     int error = 0;
@@ -38,7 +39,7 @@ BOOST_AUTO_TEST_CASE(test_categories_save)
     error = EN_getdemandname(ph, Nindex, ndem, demname);
     BOOST_REQUIRE(error == 0);
 
-    error = EN_setdemandname(ph, Nindex, ndem, (char *)"Demand category name");
+    error = EN_setdemandname(ph, Nindex, ndem, (char *)"CUB_SCOUT_MOTOR_POOL");
     BOOST_REQUIRE(error == 0);
     error = EN_saveinpfile(ph, "net1_dem_cat.inp");
     BOOST_REQUIRE(error == 0);
@@ -49,6 +50,7 @@ BOOST_AUTO_TEST_CASE(test_categories_save)
     BOOST_REQUIRE(error == 0);
 }
 
+
 BOOST_AUTO_TEST_CASE(test_categories_reopen, * boost::unit_test::depends_on("test_demand/test_categories_save"))
 {
     int error = 0;
@@ -70,9 +72,9 @@ BOOST_AUTO_TEST_CASE(test_categories_reopen, * boost::unit_test::depends_on("tes
 
     char demname[31];
     error = EN_getdemandname(ph, Nindex, ndem, demname);
-    BOOST_REQUIRE(error == 0);
+    BOOST_CHECK(error == 0);
 
-    BOOST_CHECK(check_string(demname, "Demand category name"));
+    BOOST_CHECK(check_string(demname, "CUB_SCOUT_MOTOR_POOL"));
 
     error = EN_close(ph);
     BOOST_REQUIRE(error == 0);
@@ -80,4 +82,34 @@ BOOST_AUTO_TEST_CASE(test_categories_reopen, * boost::unit_test::depends_on("tes
     BOOST_REQUIRE(error == 0);
 }
 
+BOOST_FIXTURE_TEST_CASE(test_adddemand, FixtureSingleNode)
+{
+    int key, demand_key;
+
+    error = EN_adddemand(ph, node_qhut, 100.0, "PrimaryPattern", "PrimaryDemand", &demand_key);
+    BOOST_CHECK(error != 0);
+
+    error = EN_addpattern(ph, (char *)"PrimaryPattern");
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_adddemand(ph, node_qhut, 100.0, "PrimaryPattern", "PrimaryDemand", &demand_key);
+    BOOST_CHECK(error == 0);
+
+    error = EN_addpattern(ph, (char *)"SecondaryPattern");
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_adddemand(ph, node_qhut, 10.0, "SecondaryPattern", "SecondaryDemand", &key);
+    BOOST_CHECK(error == 0);
+
+    error = EN_addpattern(ph, (char *)"TertiaryPattern");
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_adddemand(ph, node_qhut, 1.0, "TertiaryPattern", "TertiaryDemand", &demand_key);
+    BOOST_CHECK(error == 0);
+
+    error = EN_removedemand(ph, node_qhut, key);
+    BOOST_CHECK(error == 0);
+}
+
+
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/tests/test_demand_data.cpp b/tests/test_demand_data.cpp
new file mode 100644
index 0000000..bbf8526
--- /dev/null
+++ b/tests/test_demand_data.cpp
@@ -0,0 +1,295 @@
+/*
+******************************************************************************
+Project:      OWA EPANET
+Version:      2.2
+Module:       /test_demand_data.cpp
+Description:  tests demand data list node struct
+Authors:      see AUTHORS
+Copyright:    see AUTHORS
+License:      see LICENSE
+Last Updated: 04/18/2019
+******************************************************************************
+*/
+
+#define BOOST_TEST_MODULE demand_data
+#include <boost/test/unit_test.hpp>
+
+#include "demand.h"
+#include "epanet2_2.h"
+
+
+#define DATA_PATH_NET1 "./net1.inp"
+#define DATA_PATH_TMP "./tmp.inp"
+#define DATA_PATH_RPT "./test.rpt"
+#define DATA_PATH_OUT "./test.out"
+
+
+boost::test_tools::predicate_result check_string(std::string test, std::string ref)
+{
+    if (ref.compare(test) == 0)
+    return true;
+    else
+    return false;
+}
+
+
+BOOST_AUTO_TEST_SUITE(test_demand_data)
+
+
+BOOST_AUTO_TEST_CASE(test_create_destroy_demand_list)
+{
+    list_t *dlist;
+
+    dlist = create_demand_list(100.0, 1, "CUB_SCOUT_DAY_CAMP");
+    BOOST_CHECK(dlist != NULL);
+
+    delete_list(dlist);
+}
+
+
+BOOST_AUTO_TEST_CASE (test_create_destroy)
+{
+    void *data = NULL;
+
+    data = create_demand_data(100.0, 1, NULL);
+    BOOST_CHECK(data != NULL);
+
+    delete_demand_data(&data);
+
+    data = NULL;
+
+    data = create_demand_data(100.0, 1, "CUB_SCOUT_BASE_CAMP");
+    BOOST_CHECK(data != NULL);
+
+    delete_demand_data(&data);
+}
+
+BOOST_AUTO_TEST_CASE(test_get_size)
+{
+    size_t size = get_demand_data_size();
+    BOOST_CHECK(size == sizeof(demand_data_t *));
+}
+
+
+struct Fixture {
+    Fixture() {
+        _data = NULL;
+        dlist = NULL;
+
+        dlist = create_list(get_demand_data_size(), delete_demand_data);
+        _data = create_demand_data(100.0, 1, "CUB_SCOUT_BASE_CAMP");
+
+        append_list(dlist, &_data);
+    }
+    ~Fixture() {
+        delete_list(dlist);
+    }
+    demand_data_t *_data;
+    list_t *dlist;
+};
+
+BOOST_FIXTURE_TEST_CASE(test_demand_list, Fixture)
+{
+    list_node_t *lnode = head_list(dlist, false);
+    BOOST_CHECK(lnode != NULL);
+}
+
+BOOST_FIXTURE_TEST_CASE(test_demand_getset, Fixture)
+{
+    list_node_t *lnode = head_list(dlist, false);
+    double demand;
+
+    demand = get_base_demand(lnode);
+    BOOST_CHECK(demand == 100.0);
+
+    set_base_demand(lnode, 200.0);
+
+    demand = get_base_demand(lnode);
+    BOOST_CHECK(demand == 200.0);
+}
+
+BOOST_FIXTURE_TEST_CASE(test_pattern_getset, Fixture)
+{
+    list_node_t *lnode = head_list(dlist, false);
+    int index;
+
+    index = get_pattern_index(lnode);
+    BOOST_CHECK(index == 1);
+
+    set_pattern_index(lnode, 2);
+
+    index = get_pattern_index(lnode);
+    BOOST_CHECK(index == 2);
+}
+
+BOOST_FIXTURE_TEST_CASE(test_category_getset, Fixture)
+{
+    list_node_t *lnode = head_list(dlist, false);
+    char *name = NULL;
+
+    name = get_category_name(lnode);
+    BOOST_CHECK(check_string(name, (char *)"CUB_SCOUT_BASE_CAMP"));
+
+    free(name);
+    name = NULL;
+
+    set_category_name(lnode, (char *)"CUB_SCOUT_COMMAND");
+
+    name = get_category_name(lnode);
+    BOOST_CHECK(check_string(name, "CUB_SCOUT_COMMAND"));
+
+    free(name);
+}
+
+BOOST_FIXTURE_TEST_CASE(test_convert_demand, Fixture)
+{
+    list_node_t *lnode = head_list(dlist, false);
+    BOOST_CHECK(lnode != NULL);
+
+    // 100.0 GPM == 6.31 LPS
+    convert_units(lnode, 15.850);
+    double demand = get_base_demand(lnode);
+    BOOST_TEST(demand == 6.31, boost::test_tools::tolerance(0.01));
+}
+
+BOOST_AUTO_TEST_CASE(test_initclose)
+{
+    int error;
+
+    EN_Project ph = NULL;
+
+    EN_createproject(&ph);
+
+    error = EN_init(ph, DATA_PATH_RPT, DATA_PATH_OUT, EN_GPM, EN_HW);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_close(ph);
+    BOOST_REQUIRE(error == 0);
+
+    EN_deleteproject(&ph);
+}
+
+
+#define DATA_PATH_NET1 "./net1.inp"
+#define DATA_PATH_TMP "./tmp.inp"
+#define DATA_PATH_RPT "./test.rpt"
+#define DATA_PATH_OUT "./test.out"
+
+
+struct FixtureSingleNode {
+    FixtureSingleNode() {
+        error = 0;
+        ph = NULL;
+
+        EN_createproject(&ph);
+        EN_init(ph, DATA_PATH_RPT, DATA_PATH_OUT, EN_GPM, EN_HW);
+
+        EN_addnode(ph, (char *)"CUB_SCOUT_QUONSET_HUT", EN_JUNCTION, &node_qhut);
+        //EN_getnodeindex(ph, (char *)"CUB_SCOUT_QUONSET_HUT", &node_qhut);
+    }
+
+    ~FixtureSingleNode() {
+        EN_close(ph);
+        EN_deleteproject(&ph);
+    }
+    int error, index, node_qhut;
+    EN_Project ph;
+};
+
+
+BOOST_FIXTURE_TEST_CASE(test_single_node, FixtureSingleNode)
+{
+    int demand_idx, pattern_idx, n;
+    double demand;
+
+    error = EN_getnumdemands(ph, node_qhut, &n);
+    BOOST_REQUIRE(error == 0);
+    BOOST_CHECK(n == 0);
+
+    demand_idx = 1;
+    error = EN_getbasedemand(ph, node_qhut, demand_idx, &demand);
+    BOOST_REQUIRE(error == 253);
+
+    error = EN_getdemandpattern(ph, node_qhut, demand_idx, &pattern_idx);
+    BOOST_REQUIRE(error == 253);
+
+    char demname[31];
+    error = EN_getdemandname(ph, node_qhut, demand_idx, demname);
+    BOOST_REQUIRE(error == 253);
+    BOOST_CHECK(check_string(demname, "\0"));
+
+    error = EN_setbasedemand(ph, node_qhut, demand_idx, 100.0);
+    BOOST_REQUIRE(error == 0);
+
+    // only one demand category
+    pattern_idx = 1;
+    error = EN_setdemandpattern(ph, node_qhut, demand_idx, pattern_idx);
+    BOOST_REQUIRE(error == 205);
+
+    // create pattern
+    error = EN_addpattern(ph, (char *)"Pat2");
+    BOOST_REQUIRE(error == 0);
+    error = EN_getpatternindex(ph, (char *)"Pat2", &pattern_idx);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_setdemandpattern(ph, node_qhut, demand_idx, pattern_idx);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_setdemandname(ph, node_qhut, demand_idx, (char *)"CUB_SCOUT_MESS_HALL");
+    BOOST_REQUIRE(error == 0);
+
+}
+
+
+BOOST_FIXTURE_TEST_CASE(test_pattern_edits, FixtureSingleNode)
+{
+    int n, node_cpoint, pat2_idx, pat3_idx;
+
+    EN_addnode(ph, (char *)"CUB_SCOUT_CHECKPOINT", EN_JUNCTION, &node_cpoint);
+    //EN_getnodeindex(ph, (char *)"CUB_SCOUT_CHECKPOINT", &node_cpoint);
+
+    // Add 2 new patterns
+    error = EN_addpattern(ph, (char *)"DefPat");
+    BOOST_REQUIRE(error == 0);
+    error = EN_addpattern(ph, (char *)"Pat2");
+    BOOST_REQUIRE(error == 0);
+    error = EN_getpatternindex(ph, (char *)"Pat2", &pat2_idx);
+    BOOST_REQUIRE(error == 0);
+
+    error = EN_addpattern(ph, (char *)"Pat3");
+    BOOST_REQUIRE(error == 0);
+    error = EN_getpatternindex(ph, (char *)"Pat3", &pat3_idx);
+    BOOST_REQUIRE(error == 0);
+
+    double f2[] = { 2.1, 2.2 };
+    double f3[] = { 3.1, 3.2, 3.3, 3.4 };
+    error = EN_setpattern(ph, pat2_idx, f2, 2);
+    BOOST_REQUIRE(error == 0);
+    error = EN_setpattern(ph, pat3_idx, f3, 4);
+    BOOST_REQUIRE(error == 0);
+
+    // Assign Pat3 to 3rd junction
+    error = EN_setdemandpattern(ph, node_cpoint, 1, pat3_idx);
+    BOOST_REQUIRE(error == 0);
+
+    // Delete Pat2
+    error = EN_deletepattern(ph, pat2_idx);
+    BOOST_REQUIRE(error == 0);
+
+    //Check that there are now 2 patterns
+    error = EN_getcount(ph, EN_PATCOUNT, &n);
+    BOOST_REQUIRE(error == 0);
+    BOOST_CHECK(n == 2);
+
+    // Check that Pat3 with 4 factors is still assigned to 3rd junction
+    error = EN_getdemandpattern(ph, node_cpoint, 1, &pat3_idx);
+    BOOST_REQUIRE(error == 0);
+    error = EN_getpatternlen(ph, pat3_idx, &n);
+    BOOST_REQUIRE(error == 0);
+    BOOST_CHECK(n == 4);
+}
+
+
+
+
+BOOST_AUTO_TEST_SUITE_END()
diff --git a/tests/test_pattern.cpp b/tests/test_pattern.cpp
index 13d0510..596c8c0 100644
--- a/tests/test_pattern.cpp
+++ b/tests/test_pattern.cpp
@@ -18,7 +18,51 @@
 
 BOOST_AUTO_TEST_SUITE (pattern)
 
-BOOST_AUTO_TEST_CASE(add_set_pattern)
+BOOST_FIXTURE_TEST_CASE(test_set_get_default_pattern, FixtureOpenClose)
+{
+	// Assign the default pattern index
+	int defPatIdx = 1;
+	int patIdx;
+
+	// Rename the default pattern
+	error = EN_setpatternid(ph, defPatIdx, (char *)"Pat1");
+	BOOST_REQUIRE(error == 0);
+
+	error = EN_getpatternindex(ph, (char *)"Pat1", &patIdx);
+	BOOST_REQUIRE(error == 0);
+
+	BOOST_CHECK(defPatIdx == patIdx);
+}
+
+BOOST_FIXTURE_TEST_CASE(test_add_delete, FixtureOpenClose)
+{
+	double f2[] = { 2.1, 2.2 };
+	double f3[] = { 3.1, 3.2, 3.3, 3.4 };
+
+	// Add 2 new patterns
+	error = EN_addpattern(ph, (char *)"Pat2");
+	BOOST_REQUIRE(error == 0);
+	error = EN_addpattern(ph, (char *)"Pat3");
+	BOOST_REQUIRE(error == 0);
+
+	error = EN_setpattern(ph, 2, f2, 2);
+	BOOST_REQUIRE(error == 0);
+	error = EN_setpattern(ph, 3, f3, 4);
+	BOOST_REQUIRE(error == 0);
+
+	// Delete Pat2
+	error = EN_deletepattern(ph, 2);
+	BOOST_REQUIRE(error == 0);
+
+	// Check that there are now 2 patterns
+	int n;
+	error = EN_getcount(ph, EN_PATCOUNT, &n);
+	BOOST_REQUIRE(error == 0);
+	BOOST_CHECK(n == 2);
+}
+
+
+BOOST_AUTO_TEST_CASE(test_add_set)
 {
 	std::string path_inp(DATA_PATH_NET1);
 	std::string path_rpt(DATA_PATH_RPT);
@@ -34,7 +78,7 @@ BOOST_AUTO_TEST_CASE(add_set_pattern)
     BOOST_REQUIRE(error == 0);
 
     // Assign the default pattern index
-    int defPatIdx = 1;
+    int n, defPatIdx = 1;
     int patIdx;
 
     // Rename the default pattern
@@ -56,8 +100,7 @@ BOOST_AUTO_TEST_CASE(add_set_pattern)
     // Delete Pat2
     EN_deletepattern(ph, 2);
 
-    // Check that there are now 2 patterns
-    int n;
+    //Check that there are now 2 patterns
     EN_getcount(ph, EN_PATCOUNT, &n);
     BOOST_REQUIRE(n == 2);
 
diff --git a/tests/test_project.cpp b/tests/test_project.cpp
index 098f8f4..dd0c3b7 100644
--- a/tests/test_project.cpp
+++ b/tests/test_project.cpp
@@ -81,10 +81,10 @@ BOOST_AUTO_TEST_CASE(test_save)
     error = EN_saveinpfile(ph_save, "test_reopen.inp");
     BOOST_REQUIRE(error == 0);
 
-	BOOST_CHECK(boost::filesystem::exists("test_reopen.inp") == true);
+    BOOST_CHECK(boost::filesystem::exists("test_reopen.inp") == true);
 
-	error = EN_close(ph_save);
-	BOOST_REQUIRE(error == 0);
+    error = EN_close(ph_save);
+    BOOST_REQUIRE(error == 0);
     EN_deleteproject(&ph_save);
 }
 
diff --git a/tests/test_toolkit.hpp b/tests/test_toolkit.hpp
index 08f6538..b682d5d 100644
--- a/tests/test_toolkit.hpp
+++ b/tests/test_toolkit.hpp
@@ -102,6 +102,26 @@ struct FixtureAfterStep{
     EN_Project ph;
 };
 
+struct FixtureSingleNode {
+    FixtureSingleNode() {
+        error = 0;
+        ph = NULL;
+
+        EN_createproject(&ph);
+        EN_init(ph, DATA_PATH_RPT, DATA_PATH_OUT, EN_GPM, EN_HW);
+
+        EN_addnode(ph, (char *)"CUB_SCOUT_QUONSET_HUT", EN_JUNCTION, &node_qhut);
+    }
+
+    ~FixtureSingleNode() {
+        EN_close(ph);
+        EN_deleteproject(&ph);
+    }
+    int error, index, node_qhut;
+    EN_Project ph;
+};
+
+
 boost::test_tools::predicate_result check_cdd_double(std::vector<double>& test,
     std::vector<double>& ref, long cdd_tol);
 boost::test_tools::predicate_result check_string(std::string test, std::string ref);
diff --git a/tests/util/test_list.cpp b/tests/util/test_list.cpp
index 7844e6e..86fcd29 100644
--- a/tests/util/test_list.cpp
+++ b/tests/util/test_list.cpp
@@ -13,7 +13,9 @@
  ******************************************************************************
 */
 
+#include <stdlib.h>
 #include <string.h>
+#include <time.h>
 
 #define BOOST_TEST_MODULE list
 #include <boost/test/unit_test.hpp>
@@ -35,7 +37,7 @@ int *get_int_data(list_node_t *lnode) {
 
 bool iterate_int(list_node_t *lnode)
 {
-    printf("Found value: %d\n", *get_int_data(lnode));
+    printf("At Key: %d  Found value: %d\n", get_key(lnode), *get_int_data(lnode));
     return true;
 }
 
@@ -57,14 +59,22 @@ BOOST_AUTO_TEST_CASE(test_int_list){
     int i, numbers = 10;
     list_t *list = NULL;
 
+    int key[10 + 1];
+
+    srand((unsigned int)time(0));
+
     list = create_list(sizeof(int), NULL);
 
     for(i = 1; i <= numbers; i++) {
-        append_list(list, &i);
+        key[i] = append_list(list, &i);
     }
     BOOST_CHECK(size_list(list) == 10);
 
-    for_each_list(list, iterate_int);
+	listIterator iterator = (listIterator)iterate_int;
+    for_each_list(list, iterator);
+
+    list_node_t *lnode = search_list(list, key[5]);
+    BOOST_CHECK(get_key(lnode) == key[5]);
 
     delete_list(list);
 }
@@ -111,7 +121,8 @@ BOOST_FIXTURE_TEST_CASE(test_string_list, FixtureStrings) {
 
     BOOST_CHECK(size_list(list) == 5);
 
-    for_each_list(list, iterate_string);
+	listIterator iterator = (listIterator)iterate_string;
+	for_each_list(list, iterator);
 }
 
 
@@ -177,38 +188,56 @@ bool iterate_test_data(list_node_t *lnode)
 }
 
 
+char *get_name(list_node_t *lnode)
+{
+    return get_test_data(lnode)->name;
+}
 
 BOOST_AUTO_TEST_CASE(test_struct_list){
 
+    int key, head_key, tail_key;
+
     list_t *list = NULL;
     list = create_list(sizeof(test_data_t *), delete_test_data);
 
 
     test_data_t *data = create_test_data(1, "David");
-    append_list(list, &data);
+    head_key = append_list(list, &data);
 
     data = create_test_data(2, "Kevin");
-    append_list(list, &data);
+    key = append_list(list, &data);
 
     data = create_test_data(3, "Michael");
     append_list(list, &data);
 
+    data = create_test_data(4, "Craig");
+    append_list(list, &data);
 
-    BOOST_CHECK(size_list(list) == 3);
+    data = create_test_data(5, "Jimi");
+    tail_key = append_list(list, &data);
 
-    for_each_list(list, iterate_test_data);
+    BOOST_CHECK(size_list(list) == 5);
+
+	listIterator iterator = (listIterator)iterate_test_data;
+    for_each_list(list, iterator);
 
 
-    list_node_t *lnode;
-    // Iterate over list while maintaining containment of list abstraction
-    for (lnode = first_list(list); done_list(lnode); lnode = next_list(lnode)) {
-        test_data_t *test_data = get_test_data(lnode);
+    // locate a list node by a key
+    printf("Found %s!\n", get_name(search_list(list, key)));
 
-        if (test_data->num == 2)
-            printf("Found %s!\n", test_data->name);
-    }
+    printf("Removing Kevin\n");
+    remove_node(list, key);
+    for_each_list(list, iterator);
 
-    lnode = head_list(list, true);
+    printf("Removing David\n");
+    remove_node(list, head_key);
+    for_each_list(list, iterator);
+
+    printf("Removing Jimi\n");
+    remove_node(list, tail_key);
+    for_each_list(list, iterator);
+
+    list_node_t *lnode = head_list(list, true);
     delete_node(list, lnode);
 
     delete_list(list);