diff --git a/src/csharp/Grpc.Core.Tests/Internal/AsyncCallServerTest.cs b/src/csharp/Grpc.Core.Tests/Internal/AsyncCallServerTest.cs
index 0e204761f61c0513e25a0a4c0a99090cc3266d3d..dc5d8013a15282493fbc93e9c3deb14f7d8347c4 100644
--- a/src/csharp/Grpc.Core.Tests/Internal/AsyncCallServerTest.cs
+++ b/src/csharp/Grpc.Core.Tests/Internal/AsyncCallServerTest.cs
@@ -53,8 +53,6 @@ namespace Grpc.Core.Internal.Tests
         [SetUp]
         public void Init()
         {
-            var environment = GrpcEnvironment.AddRef();
-
             // Create a fake server just so we have an instance to refer to.
             // The server won't actually be used at all.
             server = new Server()
@@ -66,7 +64,6 @@ namespace Grpc.Core.Internal.Tests
             fakeCall = new FakeNativeCall();
             asyncCallServer = new AsyncCallServer<string, string>(
                 Marshallers.StringMarshaller.Serializer, Marshallers.StringMarshaller.Deserializer,
-                environment,
                 server);
             asyncCallServer.InitializeForTesting(fakeCall);
         }
@@ -75,7 +72,6 @@ namespace Grpc.Core.Internal.Tests
         public void Cleanup()
         {
             server.ShutdownAsync().Wait();
-            GrpcEnvironment.Release();
         }
 
         [Test]
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCall.cs b/src/csharp/Grpc.Core/Internal/AsyncCall.cs
index 543c7b584f6c0d8aa89b1e86edbbf74a2f30b397..045c412aaa50bab487227e6f2bda0c46f54631ee 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCall.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCall.cs
@@ -67,7 +67,7 @@ namespace Grpc.Core.Internal
         ClientSideStatus? finishedStatus;
 
         public AsyncCall(CallInvocationDetails<TRequest, TResponse> callDetails)
-            : base(callDetails.RequestMarshaller.Serializer, callDetails.ResponseMarshaller.Deserializer, callDetails.Channel.Environment)
+            : base(callDetails.RequestMarshaller.Serializer, callDetails.ResponseMarshaller.Deserializer)
         {
             this.details = callDetails.WithOptions(callDetails.Options.Normalize());
             this.initialMetadataSent = true;  // we always send metadata at the very beginning of the call.
@@ -368,7 +368,7 @@ namespace Grpc.Core.Internal
                 var credentials = details.Options.Credentials;
                 using (var nativeCredentials = credentials != null ? credentials.ToNativeCredentials() : null)
                 {
-                    var result = details.Channel.Handle.CreateCall(environment.CompletionRegistry,
+                    var result = details.Channel.Handle.CreateCall(
                                  parentCall, ContextPropagationToken.DefaultMask, cq,
                                  details.Method, details.Host, Timespec.FromDateTime(details.Options.Deadline.Value), nativeCredentials);
                     return result;
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs b/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
index 4de23706b28e5989e6288eb48d3fff7193be363a..bd1bf28da0b5cb1b98696e44c52a5585f93e2673 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCallBase.cs
@@ -58,7 +58,6 @@ namespace Grpc.Core.Internal
         readonly Func<TWrite, byte[]> serializer;
         readonly Func<byte[], TRead> deserializer;
 
-        protected readonly GrpcEnvironment environment;
         protected readonly object myLock = new object();
 
         protected INativeCall call;
@@ -78,11 +77,10 @@ namespace Grpc.Core.Internal
         protected bool initialMetadataSent;
         protected long streamingWritesCounter;  // Number of streaming send operations started so far.
 
-        public AsyncCallBase(Func<TWrite, byte[]> serializer, Func<byte[], TRead> deserializer, GrpcEnvironment environment)
+        public AsyncCallBase(Func<TWrite, byte[]> serializer, Func<byte[], TRead> deserializer)
         {
             this.serializer = GrpcPreconditions.CheckNotNull(serializer);
             this.deserializer = GrpcPreconditions.CheckNotNull(deserializer);
-            this.environment = GrpcPreconditions.CheckNotNull(environment);
         }
 
         /// <summary>
diff --git a/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs b/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
index cb9a9d4cd6f91c18b6f9b62ca006f39498800b0e..6486642e82f32e551bbedc72f8ff5e7564ab19a5 100644
--- a/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
+++ b/src/csharp/Grpc.Core/Internal/AsyncCallServer.cs
@@ -51,14 +51,14 @@ namespace Grpc.Core.Internal
         readonly CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
         readonly Server server;
 
-        public AsyncCallServer(Func<TResponse, byte[]> serializer, Func<byte[], TRequest> deserializer, GrpcEnvironment environment, Server server) : base(serializer, deserializer, environment)
+        public AsyncCallServer(Func<TResponse, byte[]> serializer, Func<byte[], TRequest> deserializer, Server server) : base(serializer, deserializer)
         {
             this.server = GrpcPreconditions.CheckNotNull(server);
         }
 
         public void Initialize(CallSafeHandle call, CompletionQueueSafeHandle completionQueue)
         {
-            call.Initialize(environment.CompletionRegistry, completionQueue);
+            call.Initialize(completionQueue);
 
             server.AddCallReference(this);
             InitializeInternal(call);
diff --git a/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs b/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
index 244b97d4a47de04739e05ce5f7e054394c3b9cf7..82361f57979acc62e2c3c2a82e8f534bf0a7ba3d 100644
--- a/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/CallSafeHandle.cs
@@ -47,16 +47,14 @@ namespace Grpc.Core.Internal
         static readonly NativeMethods Native = NativeMethods.Get();
 
         const uint GRPC_WRITE_BUFFER_HINT = 1;
-        CompletionRegistry completionRegistry;
         CompletionQueueSafeHandle completionQueue;
 
         private CallSafeHandle()
         {
         }
 
-        public void Initialize(CompletionRegistry completionRegistry, CompletionQueueSafeHandle completionQueue)
+        public void Initialize(CompletionQueueSafeHandle completionQueue)
         {
-            this.completionRegistry = completionRegistry;
             this.completionQueue = completionQueue;
         }
 
@@ -70,7 +68,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient(), context.GetReceivedMessage(), context.GetReceivedInitialMetadata()));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient(), context.GetReceivedMessage(), context.GetReceivedInitialMetadata()));
                 Native.grpcsharp_call_start_unary(this, ctx, payload, new UIntPtr((ulong)payload.Length), metadataArray, writeFlags)
                     .CheckOk();
             }
@@ -90,7 +88,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient(), context.GetReceivedMessage(), context.GetReceivedInitialMetadata()));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient(), context.GetReceivedMessage(), context.GetReceivedInitialMetadata()));
                 Native.grpcsharp_call_start_client_streaming(this, ctx, metadataArray).CheckOk();
             }
         }
@@ -100,7 +98,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient()));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient()));
                 Native.grpcsharp_call_start_server_streaming(this, ctx, payload, new UIntPtr((ulong)payload.Length), metadataArray, writeFlags).CheckOk();
             }
         }
@@ -110,7 +108,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient()));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedStatusOnClient()));
                 Native.grpcsharp_call_start_duplex_streaming(this, ctx, metadataArray).CheckOk();
             }
         }
@@ -120,7 +118,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
                 Native.grpcsharp_call_send_message(this, ctx, payload, new UIntPtr((ulong)payload.Length), writeFlags, sendEmptyInitialMetadata).CheckOk();
             }
         }
@@ -130,7 +128,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
                 Native.grpcsharp_call_send_close_from_client(this, ctx).CheckOk();
             }
         }
@@ -142,7 +140,7 @@ namespace Grpc.Core.Internal
             {
                 var ctx = BatchContextSafeHandle.Create();
                 var optionalPayloadLength = optionalPayload != null ? new UIntPtr((ulong)optionalPayload.Length) : UIntPtr.Zero;
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
                 Native.grpcsharp_call_send_status_from_server(this, ctx, status.StatusCode, status.Detail, metadataArray, sendEmptyInitialMetadata,
                     optionalPayload, optionalPayloadLength, writeFlags).CheckOk();
             }
@@ -153,7 +151,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedMessage()));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedMessage()));
                 Native.grpcsharp_call_recv_message(this, ctx).CheckOk();
             }
         }
@@ -163,7 +161,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedInitialMetadata()));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedInitialMetadata()));
                 Native.grpcsharp_call_recv_initial_metadata(this, ctx).CheckOk();
             }
         }
@@ -173,7 +171,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedCloseOnServerCancelled()));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success, context.GetReceivedCloseOnServerCancelled()));
                 Native.grpcsharp_call_start_serverside(this, ctx).CheckOk();
             }
         }
@@ -183,7 +181,7 @@ namespace Grpc.Core.Internal
             using (completionQueue.NewScope())
             {
                 var ctx = BatchContextSafeHandle.Create();
-                completionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
+                completionQueue.CompletionRegistry.RegisterBatchCompletion(ctx, (success, context) => callback(success));
                 Native.grpcsharp_call_send_initial_metadata(this, ctx, metadataArray).CheckOk();
             }
         }
diff --git a/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs b/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
index 1dbd1f4e34cb7bac20513017ce4ef3de8d71dda0..a83deaa26f1b98f1c263e8ffa61858e9dcca5268 100644
--- a/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/ChannelSafeHandle.cs
@@ -63,7 +63,7 @@ namespace Grpc.Core.Internal
             return Native.grpcsharp_secure_channel_create(credentials, target, channelArgs);
         }
 
-        public CallSafeHandle CreateCall(CompletionRegistry registry, CallSafeHandle parentCall, ContextPropagationFlags propagationMask, CompletionQueueSafeHandle cq, string method, string host, Timespec deadline, CallCredentialsSafeHandle credentials)
+        public CallSafeHandle CreateCall(CallSafeHandle parentCall, ContextPropagationFlags propagationMask, CompletionQueueSafeHandle cq, string method, string host, Timespec deadline, CallCredentialsSafeHandle credentials)
         {
             using (Profilers.ForCurrentThread().NewScope("ChannelSafeHandle.CreateCall"))
             {
@@ -72,7 +72,7 @@ namespace Grpc.Core.Internal
                 {
                     result.SetCredentials(credentials);
                 }
-                result.Initialize(registry, cq);
+                result.Initialize(cq);
                 return result;
             }
         }
diff --git a/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs b/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs
index 91364cdc70a0b249d476f45eb4ac0d6226e541a0..46f562422315ef5737281dff18c4528de9089e63 100644
--- a/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs
+++ b/src/csharp/Grpc.Core/Internal/CompletionQueueSafeHandle.cs
@@ -45,6 +45,7 @@ namespace Grpc.Core.Internal
         static readonly NativeMethods Native = NativeMethods.Get();
 
         AtomicCounter shutdownRefcount = new AtomicCounter(1);
+        CompletionRegistry completionRegistry;
 
         private CompletionQueueSafeHandle()
         {
@@ -53,7 +54,13 @@ namespace Grpc.Core.Internal
         public static CompletionQueueSafeHandle Create()
         {
             return Native.grpcsharp_completion_queue_create();
+        }
 
+        public static CompletionQueueSafeHandle Create(CompletionRegistry completionRegistry)
+        {
+            var cq = Native.grpcsharp_completion_queue_create();
+            cq.completionRegistry = completionRegistry;
+            return cq;
         }
 
         public CompletionQueueEvent Next()
@@ -83,6 +90,15 @@ namespace Grpc.Core.Internal
             DecrementShutdownRefcount();
         }
 
+        /// <summary>
+        /// Completion registry associated with this completion queue.
+        /// Doesn't need to be set if only using Pluck() operations.
+        /// </summary>
+        public CompletionRegistry CompletionRegistry
+        {
+            get { return completionRegistry; }
+        }
+
         protected override bool ReleaseHandle()
         {
             Native.grpcsharp_completion_queue_destroy(handle);
diff --git a/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs b/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
index 27dcea71188669a8c836be656a48eb6fe5efc66d..4059247e30722ea79499f8cf22a2d32184c2a342 100644
--- a/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
+++ b/src/csharp/Grpc.Core/Internal/GrpcThreadPool.cs
@@ -75,7 +75,7 @@ namespace Grpc.Core.Internal
             lock (myLock)
             {
                 GrpcPreconditions.CheckState(completionQueues == null, "Already started.");
-                completionQueues = CreateCompletionQueueList(completionQueueCount);
+                completionQueues = CreateCompletionQueueList(environment, completionQueueCount);
 
                 for (int i = 0; i < poolSize; i++)
                 {
@@ -152,12 +152,13 @@ namespace Grpc.Core.Internal
             while (ev.type != CompletionQueueEvent.CompletionType.Shutdown);
         }
 
-        private static IReadOnlyCollection<CompletionQueueSafeHandle> CreateCompletionQueueList(int completionQueueCount)
+        private static IReadOnlyCollection<CompletionQueueSafeHandle> CreateCompletionQueueList(GrpcEnvironment environment, int completionQueueCount)
         {
             var list = new List<CompletionQueueSafeHandle>();
             for (int i = 0; i < completionQueueCount; i++)
             {
-                list.Add(CompletionQueueSafeHandle.Create());
+                var completionRegistry = new CompletionRegistry(environment);
+                list.Add(CompletionQueueSafeHandle.Create(completionRegistry));
             }
             return list.AsReadOnly();
         }
diff --git a/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs b/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs
index e4c9acc0999a15ced08d960f518e509f528edefe..6a2f52016361cef5469b4b389e4fe36e99ae040d 100644
--- a/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs
+++ b/src/csharp/Grpc.Core/Internal/ServerCallHandler.cs
@@ -44,7 +44,7 @@ namespace Grpc.Core.Internal
 {
     internal interface IServerCallHandler
     {
-        Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment, CompletionQueueSafeHandle cq);
+        Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq);
     }
 
     internal class UnaryServerCallHandler<TRequest, TResponse> : IServerCallHandler
@@ -62,12 +62,12 @@ namespace Grpc.Core.Internal
             this.handler = handler;
         }
 
-        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment, CompletionQueueSafeHandle cq)
+        public async Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
         {
             var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                 method.ResponseMarshaller.Serializer,
                 method.RequestMarshaller.Deserializer,
-                environment, newRpc.Server);
+                newRpc.Server);
 
             asyncCall.Initialize(newRpc.Call, cq);
             var finishedTask = asyncCall.ServerSideCallAsync();
@@ -121,12 +121,12 @@ namespace Grpc.Core.Internal
             this.handler = handler;
         }
 
-        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment, CompletionQueueSafeHandle cq)
+        public async Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
         {
             var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                 method.ResponseMarshaller.Serializer,
                 method.RequestMarshaller.Deserializer,
-                environment, newRpc.Server);
+                newRpc.Server);
 
             asyncCall.Initialize(newRpc.Call, cq);
             var finishedTask = asyncCall.ServerSideCallAsync();
@@ -179,12 +179,12 @@ namespace Grpc.Core.Internal
             this.handler = handler;
         }
 
-        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment, CompletionQueueSafeHandle cq)
+        public async Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
         {
             var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                 method.ResponseMarshaller.Serializer,
                 method.RequestMarshaller.Deserializer,
-                environment, newRpc.Server);
+                newRpc.Server);
 
             asyncCall.Initialize(newRpc.Call, cq);
             var finishedTask = asyncCall.ServerSideCallAsync();
@@ -237,12 +237,12 @@ namespace Grpc.Core.Internal
             this.handler = handler;
         }
 
-        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment, CompletionQueueSafeHandle cq)
+        public async Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
         {
             var asyncCall = new AsyncCallServer<TRequest, TResponse>(
                 method.ResponseMarshaller.Serializer,
                 method.RequestMarshaller.Deserializer,
-                environment, newRpc.Server);
+                newRpc.Server);
 
             asyncCall.Initialize(newRpc.Call, cq);
             var finishedTask = asyncCall.ServerSideCallAsync();
@@ -281,11 +281,11 @@ namespace Grpc.Core.Internal
     {
         public static readonly NoSuchMethodCallHandler Instance = new NoSuchMethodCallHandler();
 
-        public async Task HandleCall(ServerRpcNew newRpc, GrpcEnvironment environment, CompletionQueueSafeHandle cq)
+        public async Task HandleCall(ServerRpcNew newRpc, CompletionQueueSafeHandle cq)
         {
             // We don't care about the payload type here.
             var asyncCall = new AsyncCallServer<byte[], byte[]>(
-                (payload) => payload, (payload) => payload, environment, newRpc.Server);
+                (payload) => payload, (payload) => payload, newRpc.Server);
             
             asyncCall.Initialize(newRpc.Call, cq);
             var finishedTask = asyncCall.ServerSideCallAsync();
diff --git a/src/csharp/Grpc.Core/Server.cs b/src/csharp/Grpc.Core/Server.cs
index 6507f6e672292184eb2472c533de30b372908f06..b66de8178924dd613094f4b152953df1c4c9392f 100644
--- a/src/csharp/Grpc.Core/Server.cs
+++ b/src/csharp/Grpc.Core/Server.cs
@@ -280,7 +280,7 @@ namespace Grpc.Core
                 {
                     callHandler = NoSuchMethodCallHandler.Instance;
                 }
-                await callHandler.HandleCall(newRpc, environment, cq).ConfigureAwait(false);
+                await callHandler.HandleCall(newRpc, cq).ConfigureAwait(false);
             }
             catch (Exception e)
             {