Class That Uses Sql Server Isn't Releasing Memory

I'm running into a problem where the class I'm running seems to eat up a lot of memory with sql server.  When it's done running, the memory usage never goes down in taskmanager.  I can't figure out where the memory leak might be.  Here's the code that is being called.  Does anyone see a reason why it would continue to eat memory as it runs and then not release it?  Thanks.

 using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;

namespace QueryLoadTester
{
class JobSeeker
{
private string ConStr = @"Data Source=server;Initial Catalog=db;Integrated Security=True";

public JobSeeker() { }

#region UpdateJobSeeker
public void UpdateJobSeeker(string JobSeekerId)
{
string qry = "SELECT top 100 dbo.JobSeeker.JobSeekerID, dbo.JobSeeker.SiteId, dbo.JobSeeker.PositionTitle, dbo.JobSeeker.LocationID, dbo.JobSeeker.CurrentSalary, " +
"dbo.JobSeeker.DesiredSalary, dbo.JobSeeker.MinSalary, dbo.JobSeeker.CurrentHourly, dbo.JobSeeker.MinHourly, dbo.JobSeeker.Comments, " +
"dbo.JobSeeker.Resume, dbo.JobSeeker.WillRelocate, dbo.JobSeeker.DateAdded, dbo.JobSeeker.LastModified FROM dbo.JobSeeker " +
"where dbo.JobSeeker.Active=1 and dbo.JobSeeker.samplejobseeker=0 ";

if (JobSeekerId.Length > 0)
qry += " and dbo.JobSeeker.JobSeekerID=" + JobSeekerId;

qry += " and dbo.JobSeeker.JobSeekerID not in (Select JobSeekerId from JobSeekerFullTextSearch)";

SqlConnection cnInsert = new SqlConnection(ConStr);
SqlDataAdapter adp = new SqlDataAdapter(qry, cnInsert);
cnInsert.Open();
DataSet dsJobSeekers = new DataSet();
adp.Fill(dsJobSeekers);
adp.Dispose(); adp = null;


if (dsJobSeekers.Tables[0].Rows.Count > 0)
{
string jid = string.Empty;
string degree, degreegroup;
StringBuilder sb = new StringBuilder();
SqlCommand cmdInsert = new SqlCommand();
cmdInsert.Connection = cnInsert;

foreach (DataRow dr in dsJobSeekers.Tables[0].Rows)
{
jid = dr["JobSeekerID"].ToString();

if (JobSeekerId.Length > 0)
{
cmdInsert.CommandText = "Delete from JobSeekerFullTextSearch where JobSeekerId=" + JobSeekerId;
cmdInsert.ExecuteNonQuery();
}

DataSet dsExtras = GetJobSeekerExtras(jid, cnInsert);

SqlTransaction trans = cnInsert.BeginTransaction();
cmdInsert.Transaction = trans;

degree = degreegroup = string.Empty;

#region insert record into fulltextsearch
try
{
sb.Remove(0, sb.Length);
sb.Append("Insert into JobSeekerFullTextSearch (JobSeekerId, PositionTitle, LocationID, CurrentSalary, ");
sb.Append("DesiredSalary, MinSalary, CurrentHourly, MinHourly, CommentsResume, SiteId, WillRelocate, DateAdded, LastModified) values (");
sb.Append(jid);
sb.Append(",'");
sb.Append(dr["PositionTitle"].ToString().Replace("'", "''"));
sb.Append("',");
sb.Append("'");
sb.Append(dr["LocationID"].ToString().Replace("'", "''"));
sb.Append("',");
sb.Append(Nullify(dr["CurrentSalary"]));
sb.Append(",");
sb.Append(Nullify(dr["DesiredSalary"]));
sb.Append(",");
sb.Append(Nullify(dr["MinSalary"]));
sb.Append(",");
sb.Append(Nullify(dr["CurrentHourly"]));
sb.Append(",");
sb.Append(Nullify(dr["MinHourly"]));
sb.Append(",'");
sb.Append(dr["Comments"].ToString().Replace("'", "''"));
sb.Append(" ");
sb.Append(dr["Resume"].ToString().Replace("'", "''"));
sb.Append("',");
sb.Append(dr["SiteId"].ToString());
sb.Append(",");
sb.Append(Convert.ToInt32(Convert.ToBoolean(dr["WillRelocate"].ToString())));
sb.Append(",'");
sb.Append(dr["DateAdded"].ToString());
sb.Append("','");
sb.Append(dr["LastModified"].ToString());
sb.Append("')");

cmdInsert.CommandText = sb.ToString();

cmdInsert.ExecuteNonQuery();

#region dsExtras insert
//degree info
if (dsExtras.Tables.Count > 0 && dsExtras.Tables[0].Rows.Count > 0)
{
degree = dsExtras.Tables[0].Rows[0][0].ToString();
degreegroup = dsExtras.Tables[0].Rows[0][1].ToString();

if (degree.Length > 0 || degreegroup.Length > 0)
{
sb.Remove(0, sb.Length);
sb.Append("Update JobSeekerFullTextSearch set DegreeLevel='");
sb.Append(degree);
sb.Append("', DegreeLevelGroup=");
sb.Append(degreegroup);
sb.Append(" where JobSeekerId=");
sb.Append(jid);
cmdInsert.CommandText = sb.ToString();
cmdInsert.ExecuteNonQuery();
}
}

//disciplines info
if (dsExtras.Tables.Count > 1 && dsExtras.Tables[1].Rows.Count > 0)
{
sb.Remove(0, sb.Length);

foreach (DataRow d in dsExtras.Tables[1].Rows)
{
sb.Append(d[0].ToString());
sb.Append(",");
}
if (sb.ToString().Length > 0)
{
cmdInsert.CommandText = "Update JobSeekerFullTextSearch set DisciplineIdList='" + sb.ToString().Substring(0, sb.ToString().Length - 1) + "' where JobSeekerId=" + jid;
cmdInsert.ExecuteNonQuery();
}
}

//industries info
if (dsExtras.Tables.Count > 2 && dsExtras.Tables[2].Rows.Count > 0)
{
sb.Remove(0, sb.Length);

foreach (DataRow d in dsExtras.Tables[2].Rows)
{
sb.Append(d[0].ToString());
sb.Append(",");
}
if (sb.ToString().Length > 0)
{
cmdInsert.CommandText = "Update JobSeekerFullTextSearch set IndustryIdList='" + sb.ToString().Substring(0, sb.ToString().Length - 1) + "' where JobSeekerId=" + jid;
cmdInsert.ExecuteNonQuery();
}
}


//jobtypes info
if (dsExtras.Tables.Count > 3 && dsExtras.Tables[3].Rows.Count > 0)
{
sb.Remove(0, sb.Length);

foreach (DataRow d in dsExtras.Tables[3].Rows)
{
sb.Append(d[0].ToString());
sb.Append(",");
}
if (sb.ToString().Length > 0)
{
cmdInsert.CommandText = "Update JobSeekerFullTextSearch set JobTypeIdList='" + sb.ToString().Substring(0, sb.ToString().Length - 1) + "' where JobSeekerId=" + jid;
cmdInsert.ExecuteNonQuery();
}
}
#endregion

trans.Commit();
Console.WriteLine("Insert for " + jid);
}
catch (Exception exc)
{
trans.Rollback();
Console.WriteLine(jid + " - " + exc.ToString());
}
finally
{
trans.Dispose(); trans = null;
}
#endregion

dsExtras.Clear(); dsExtras.Dispose(); dsExtras = null;

}//end foreach
cmdInsert.Dispose(); cmdInsert = null;
}
cnInsert.Close(); cnInsert.Dispose(); cnInsert = null;
GC.Collect();
}
#endregion

#region GetJobSeekerExtras
private static DataSet GetJobSeekerExtras(string JobSeekerId, SqlConnection cn)
{
string qry = "Select JobSeekerDegree.DegreeLevel, VDegreeLevels.DegreeGroup from JobSeekerDegree inner join " +
" VDegreeLevels on JobSeekerDegree.DegreeLevel=VDegreeLevels.DegreeLevel where JobSeekerId=" + JobSeekerId + ";" +
"Select DisciplineID from JobSeekerDiscipline where JobSeekerId=" + JobSeekerId + ";" +
"Select IndustryID from JobSeekerIndustry where JobSeekerID=" + JobSeekerId + ";" +
"Select JobTypeID from JobSeekerJobType where JobSeekerID=" + JobSeekerId;

DataSet ds = new DataSet();
SqlDataAdapter adp = new SqlDataAdapter(qry, cn);
adp.Fill(ds);
adp.Dispose(); adp = null;
return ds;

}
#endregion

#region Nullify
private static string Nullify(object p)
{
if (p != System.DBNull.Value)
return p.ToString();
else
return "null";
}
#endregion
}
}