diff --git a/cadcAccessControl-Server/build.xml b/cadcAccessControl-Server/build.xml
index 2b3c41636f7819ddbcb476d722cf5a6f33395301..49e3a291cd17ad61a98f2867dd8a2deefe3a24e5 100644
--- a/cadcAccessControl-Server/build.xml
+++ b/cadcAccessControl-Server/build.xml
@@ -115,6 +115,9 @@
     <mkdir dir="${user.home}/config" />
     <copy overwrite="true" file="test/LdapConfig.test.properties"
           todir="${user.home}/config/"/>
+    <copy overwrite="true"
+          file="${env.CADC_PREFIX}/etc/LocalAuthority.properties"
+          tofile="${build}/class/LocalAuthority.properties"/>
   </target>
 
   <!-- JAR files needed to run the test suite -->
diff --git a/cadcAccessControl-Server/src/ca/nrc/cadc/ac/server/ldap/LdapUserDAO.java b/cadcAccessControl-Server/src/ca/nrc/cadc/ac/server/ldap/LdapUserDAO.java
index 14b32069061edc9b17d427adb131e6fdff5011a2..9ebf865785f07b009c00586a316aff69c59262b4 100755
--- a/cadcAccessControl-Server/src/ca/nrc/cadc/ac/server/ldap/LdapUserDAO.java
+++ b/cadcAccessControl-Server/src/ca/nrc/cadc/ac/server/ldap/LdapUserDAO.java
@@ -1273,11 +1273,6 @@ public class LdapUserDAO extends LdapDAO
         return uuid.getLeastSignificantBits();
     }
 
-    protected void setInternalIdUriPrefix(String internalIdUriPrefix)
-    {
-        this.internalIdUriPrefix = internalIdUriPrefix;
-    }
-
     protected InternalID getInternalID(String numericID)
     {
         UUID uuid = new UUID(0L, Long.parseLong(numericID));
diff --git a/cadcAccessControl-Server/src/ca/nrc/cadc/ac/server/web/WhoAmIServlet.java b/cadcAccessControl-Server/src/ca/nrc/cadc/ac/server/web/WhoAmIServlet.java
index e97e1165c0f34c114fc119e6df08063d854beba8..9caff6d55d45577b28998d2061987f496f3ba459 100644
--- a/cadcAccessControl-Server/src/ca/nrc/cadc/ac/server/web/WhoAmIServlet.java
+++ b/cadcAccessControl-Server/src/ca/nrc/cadc/ac/server/web/WhoAmIServlet.java
@@ -81,10 +81,10 @@ import javax.servlet.http.HttpServletResponse;
 
 import org.apache.log4j.Logger;
 
-import ca.nrc.cadc.ac.AC;
 import ca.nrc.cadc.auth.AuthenticationUtil;
 import ca.nrc.cadc.auth.HttpPrincipal;
 import ca.nrc.cadc.log.ServletLogInfo;
+import ca.nrc.cadc.reg.client.LocalAuthority;
 import ca.nrc.cadc.reg.client.RegistryClient;
 
 /**
@@ -164,9 +164,15 @@ public class WhoAmIServlet extends HttpServlet
                   final String scheme) throws IOException
     {
         final RegistryClient registryClient = getRegistryClient();
+
+        LocalAuthority localAuthority = new LocalAuthority();
+        URI umsServiceURI = localAuthority.getServiceURI("ums");
+
+        log.debug("ums service uri: " + umsServiceURI);
+
         final URL redirectURL =
                 registryClient.getServiceURL(
-                        URI.create(AC.UMS_SERVICE_URI + "#users"), scheme, USER_GET_PATH);
+                        URI.create(umsServiceURI.toString() + "#users"), scheme, USER_GET_PATH);
 
         // Take the first one.
         final String redirectUrl =
diff --git a/cadcAccessControl-Server/test/src/ca/nrc/cadc/ac/server/web/WhoAmIServletTest.java b/cadcAccessControl-Server/test/src/ca/nrc/cadc/ac/server/web/WhoAmIServletTest.java
index 5e8a06a3de1c0ce9fa21ef4ed1e039980b189add..63d4d6413d32aafe311a93d7ec81e3c07c95f254 100644
--- a/cadcAccessControl-Server/test/src/ca/nrc/cadc/ac/server/web/WhoAmIServletTest.java
+++ b/cadcAccessControl-Server/test/src/ca/nrc/cadc/ac/server/web/WhoAmIServletTest.java
@@ -84,8 +84,8 @@ import javax.servlet.http.HttpServletResponse;
 
 import org.junit.Test;
 
-import ca.nrc.cadc.ac.AC;
 import ca.nrc.cadc.auth.HttpPrincipal;
+import ca.nrc.cadc.reg.client.LocalAuthority;
 import ca.nrc.cadc.reg.client.RegistryClient;
 
 
@@ -132,7 +132,10 @@ public class WhoAmIServletTest
         mockResponse.sendRedirect("/ac/users/CADCtest?idType=HTTP");
         expectLastCall().once();
 
-        expect(mockRegistry.getServiceURL(URI.create(AC.UMS_SERVICE_URI + "#users"),
+        LocalAuthority localAuthority = new LocalAuthority();
+        URI umsServiceURI = localAuthority.getServiceURI("ums");
+
+        expect(mockRegistry.getServiceURL(URI.create(umsServiceURI.toString() + "#users"),
                                           "http", "/%s?idType=HTTP")).
                 andReturn(new URL("http://mysite.com/ac/users/CADCtest?idType=HTTP")).once();
 
diff --git a/cadcAccessControl-Server/test/src/ca/nrc/cadc/ac/server/web/groups/RemoveUserMemberActionTest.java b/cadcAccessControl-Server/test/src/ca/nrc/cadc/ac/server/web/groups/RemoveUserMemberActionTest.java
index d12fc441d495414ac8b4fa84b6df56af7750392f..ac1960db076b6f6a66d7fa18b14fde362988d7f1 100644
--- a/cadcAccessControl-Server/test/src/ca/nrc/cadc/ac/server/web/groups/RemoveUserMemberActionTest.java
+++ b/cadcAccessControl-Server/test/src/ca/nrc/cadc/ac/server/web/groups/RemoveUserMemberActionTest.java
@@ -77,10 +77,6 @@ import java.util.UUID;
 
 import javax.security.auth.x500.X500Principal;
 
-import ca.nrc.cadc.ac.AC;
-import ca.nrc.cadc.ac.InternalID;
-import ca.nrc.cadc.auth.HttpPrincipal;
-import ca.nrc.cadc.util.ObjectUtil;
 import org.apache.log4j.Level;
 import org.apache.log4j.Logger;
 import org.easymock.EasyMock;
@@ -88,13 +84,17 @@ import org.junit.BeforeClass;
 import org.junit.Test;
 
 import ca.nrc.cadc.ac.Group;
+import ca.nrc.cadc.ac.InternalID;
 import ca.nrc.cadc.ac.MemberNotFoundException;
 import ca.nrc.cadc.ac.User;
 import ca.nrc.cadc.ac.server.GroupPersistence;
 import ca.nrc.cadc.ac.server.UserPersistence;
 import ca.nrc.cadc.auth.AuthenticationUtil;
+import ca.nrc.cadc.auth.HttpPrincipal;
 import ca.nrc.cadc.auth.IdentityType;
+import ca.nrc.cadc.reg.client.LocalAuthority;
 import ca.nrc.cadc.util.Log4jInit;
+import ca.nrc.cadc.util.ObjectUtil;
 
 /**
  *
@@ -117,7 +117,9 @@ public class RemoveUserMemberActionTest
         try
         {
             User user = new User();
-            InternalID internalID = new InternalID(new URI(AC.USER_URI + "?" + UUID.randomUUID()));
+            LocalAuthority localAuthority = new LocalAuthority();
+            URI umsServiceURI = localAuthority.getServiceURI("ums");
+            InternalID internalID = new InternalID(new URI(umsServiceURI.toASCIIString() + "?" + UUID.randomUUID()));
             ObjectUtil.setField(user, internalID, "id");
 
             String userID = "cn=foo,c=ca";
@@ -169,7 +171,9 @@ public class RemoveUserMemberActionTest
         try
         {
             User user = new User();
-            InternalID internalID = new InternalID(new URI(AC.USER_URI + "?" + UUID.randomUUID()));
+            LocalAuthority localAuthority = new LocalAuthority();
+            URI umsServiceURI = localAuthority.getServiceURI("ums");
+            InternalID internalID = new InternalID(new URI(umsServiceURI.toString() + "?" + UUID.randomUUID()));
             ObjectUtil.setField(user, internalID, "id");
 
             String userID = "cn=foo,c=ca";
diff --git a/cadcAccessControl/build.xml b/cadcAccessControl/build.xml
index 31a66f35a13c41c0a51f78908a5329d33374a6c2..8e0cefd4de16e111791d16f73e001e11f30435ae 100644
--- a/cadcAccessControl/build.xml
+++ b/cadcAccessControl/build.xml
@@ -114,6 +114,12 @@
     <property name="jsonassert" value="${ext.dev}/jsonassert.jar" />
     
     <property name="testingJars" value="${build}/class:${jsonassert}:${jars}:${xerces}:${asm}:${cglib}:${easymock}:${junit}:${objenesis}" />
+	
+	<target name="setup-test">
+        <copy overwrite="true"
+              file="${env.CADC_PREFIX}/etc/LocalAuthority.properties"
+              tofile="${build}/class/LocalAuthority.properties"/>
+	</target>
 
     <target name="single-test" depends="compile,compile-test">
         <echo message="Running test suite..." />
diff --git a/cadcAccessControl/src/ca/nrc/cadc/ac/AC.java b/cadcAccessControl/src/ca/nrc/cadc/ac/AC.java
index be1fa3be7f4b419f11ba654fc147562ce5904d38..f30c3fdf5ffeeec62692cb0822c00bc0e69df15e 100755
--- a/cadcAccessControl/src/ca/nrc/cadc/ac/AC.java
+++ b/cadcAccessControl/src/ca/nrc/cadc/ac/AC.java
@@ -85,10 +85,4 @@ public class AC
     // Denotes a group readable by public
     public static final String PROPERTY_PUBLIC = "ivo://ivoa.net/gms#public";
 
-    public static final String UMS_SERVICE_URI = "ivo://cadc.nrc.ca/ums";
-    public static final String GMS_SERVICE_URI = "ivo://cadc.nrc.ca/gms";
-
-    // Group URI attribute once the group name is appended
-    public static final String GROUP_URI = "ivo://cadc.nrc.ca/gms#";
-
 }
diff --git a/cadcAccessControl/src/ca/nrc/cadc/ac/xml/AbstractReaderWriter.java b/cadcAccessControl/src/ca/nrc/cadc/ac/xml/AbstractReaderWriter.java
index 242f0456561a587853843100ccc0fcb74b30d21a..3940001c3fbda7a85575baa46a936ea296d9db37 100644
--- a/cadcAccessControl/src/ca/nrc/cadc/ac/xml/AbstractReaderWriter.java
+++ b/cadcAccessControl/src/ca/nrc/cadc/ac/xml/AbstractReaderWriter.java
@@ -69,7 +69,26 @@
 
 package ca.nrc.cadc.ac.xml;
 
-import ca.nrc.cadc.ac.AC;
+import java.io.IOException;
+import java.io.Writer;
+import java.lang.reflect.Field;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.security.Principal;
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.util.List;
+import java.util.Set;
+import java.util.UUID;
+
+import javax.security.auth.x500.X500Principal;
+
+import org.jdom2.Attribute;
+import org.jdom2.Document;
+import org.jdom2.Element;
+import org.jdom2.output.Format;
+import org.jdom2.output.XMLOutputter;
+
 import ca.nrc.cadc.ac.Group;
 import ca.nrc.cadc.ac.GroupProperty;
 import ca.nrc.cadc.ac.InternalID;
@@ -85,24 +104,7 @@ import ca.nrc.cadc.auth.IdentityType;
 import ca.nrc.cadc.auth.NumericPrincipal;
 import ca.nrc.cadc.auth.OpenIdPrincipal;
 import ca.nrc.cadc.date.DateUtil;
-import org.jdom2.Attribute;
-import org.jdom2.Document;
-import org.jdom2.Element;
-import org.jdom2.output.Format;
-import org.jdom2.output.XMLOutputter;
-
-import javax.security.auth.x500.X500Principal;
-import java.io.IOException;
-import java.io.Writer;
-import java.lang.reflect.Field;
-import java.net.URI;
-import java.net.URISyntaxException;
-import java.security.Principal;
-import java.text.DateFormat;
-import java.text.ParseException;
-import java.util.List;
-import java.util.Set;
-import java.util.UUID;
+import ca.nrc.cadc.reg.client.LocalAuthority;
 
 /**
  * AbstractReaderWriter TODO describe class
@@ -149,6 +151,15 @@ public abstract class AbstractReaderWriter
     public static final String USER_MEMBERS = "userMembers";
     public static final String USER_REQUEST = "userRequest";
 
+    private String gmsServiceURI;
+
+    public AbstractReaderWriter()
+    {
+        LocalAuthority localAuthority = new LocalAuthority();
+        URI serviceURI = localAuthority.getServiceURI("gms");
+        gmsServiceURI = serviceURI.toString();
+    }
+
     /**
      * Write to root Element to a writer.
      *
@@ -469,13 +480,13 @@ public abstract class AbstractReaderWriter
         }
 
         // Group groupID
-        int index = uri.indexOf(AC.GROUP_URI);
+        int index = uri.indexOf(gmsServiceURI);
         if (index == -1)
         {
             String error = "group uri attribute malformed: " + uri;
             throw new ReaderException(error);
         }
-        String groupID = uri.substring(AC.GROUP_URI.length());
+        String groupID = uri.substring(gmsServiceURI.length() + 1);
 
         // Group owner
         User user = null;
@@ -922,7 +933,7 @@ public abstract class AbstractReaderWriter
 
         // Create the root group element.
         Element groupElement = new Element(GROUP);
-        String groupURI = AC.GROUP_URI + group.getID();
+        String groupURI = gmsServiceURI + "#" + group.getID();
         groupElement.setAttribute(new Attribute(URI, groupURI));
 
         // Group owner
diff --git a/cadcAccessControl/test/src/ca/nrc/cadc/ac/client/UserClientTest.java b/cadcAccessControl/test/src/ca/nrc/cadc/ac/client/UserClientTest.java
index 067d5ab6b8f24d430ff5b063b41b3c483c8e0822..8217c0857dee9d9f1dea42d2b4cf1ec33bc0ca2b 100644
--- a/cadcAccessControl/test/src/ca/nrc/cadc/ac/client/UserClientTest.java
+++ b/cadcAccessControl/test/src/ca/nrc/cadc/ac/client/UserClientTest.java
@@ -84,10 +84,9 @@ import org.apache.log4j.Logger;
 import org.junit.Assert;
 import org.junit.Test;
 
-import ca.nrc.cadc.ac.AC;
 import ca.nrc.cadc.auth.HttpPrincipal;
 import ca.nrc.cadc.auth.NumericPrincipal;
-import ca.nrc.cadc.reg.client.RegistryClient;
+import ca.nrc.cadc.reg.client.LocalAuthority;
 import ca.nrc.cadc.util.Log4jInit;
 
 
@@ -96,9 +95,13 @@ public class UserClientTest
 
     private static final Logger log = Logger.getLogger(UserClientTest.class);
 
+    private URI umsServiceURI;
+
     public UserClientTest()
     {
         Log4jInit.setLevel("ca.nrc.cadc.ac", Level.INFO);
+        LocalAuthority localAuthority = new LocalAuthority();
+        umsServiceURI = localAuthority.getServiceURI("ums");
     }
 
     @Test
@@ -178,9 +181,7 @@ public class UserClientTest
 
     protected UserClient createUserClient() throws URISyntaxException, MalformedURLException
     {
-    	RegistryClient regClient = new RegistryClient();
-    	URI serviceURI = new URI(AC.UMS_SERVICE_URI);
-    	return new UserClient(serviceURI);
+    	return new UserClient(umsServiceURI);
 
     }
 
@@ -189,7 +190,7 @@ public class UserClientTest
     {
         try
         {
-            UserClient c = new UserClient(new URI(AC.UMS_SERVICE_URI));
+            UserClient c = new UserClient(umsServiceURI);
 
             Subject s = new Subject();
             s.getPrincipals().add(new HttpPrincipal("bob"));
@@ -209,7 +210,7 @@ public class UserClientTest
     {
         try
         {
-            UserClient c = new UserClient(new URI(AC.UMS_SERVICE_URI));
+            UserClient c = new UserClient(umsServiceURI);
 
             Subject s = new Subject();
             s.getPrincipals().add(new HttpPrincipal("bob"));
@@ -231,7 +232,7 @@ public class UserClientTest
     {
         try
         {
-            UserClient c = new UserClient(new URI(AC.UMS_SERVICE_URI));
+            UserClient c = new UserClient(umsServiceURI);
 
             Subject s = new Subject();
             UUID uuid = UUID.randomUUID();
@@ -253,7 +254,7 @@ public class UserClientTest
     {
         try
         {
-            UserClient c = new UserClient(new URI(AC.UMS_SERVICE_URI));
+            UserClient c = new UserClient(umsServiceURI);
 
             Subject s = new Subject();
             UUID uuid = UUID.randomUUID();
diff --git a/cadcTomcat/src/ca/nrc/cadc/tomcat/CadcBasicAuthenticator.java b/cadcTomcat/src/ca/nrc/cadc/tomcat/CadcBasicAuthenticator.java
index d27a2f83476821f3a0b66631f314710452fe4322..eb8b69e40736cbae2265a7b8de3b6d1eb6a73e79 100644
--- a/cadcTomcat/src/ca/nrc/cadc/tomcat/CadcBasicAuthenticator.java
+++ b/cadcTomcat/src/ca/nrc/cadc/tomcat/CadcBasicAuthenticator.java
@@ -71,7 +71,6 @@ package ca.nrc.cadc.tomcat;
 
 import java.io.IOException;
 import java.net.HttpURLConnection;
-import java.net.MalformedURLException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
@@ -79,11 +78,6 @@ import java.security.Principal;
 import java.util.Arrays;
 import java.util.List;
 
-import org.apache.catalina.realm.GenericPrincipal;
-import org.apache.catalina.realm.RealmBase;
-import org.apache.log4j.Level;
-import org.apache.log4j.Logger;
-
 /**
  * Custom class for Tomcat realm authentication.
  *
@@ -98,7 +92,7 @@ public class CadcBasicAuthenticator extends RealmBase
 {
 
     private static Logger log = Logger.getLogger(CadcBasicAuthenticator.class);
-    private static final String AC_URI = "ivo://canfar.net/ums";
+    private static final String AC_URI = "ivo://cadc.nrc.ca/ums";
 
     static
     {