Postgresql NpgSql connection handling extra query and multiple close connection

I am basically running a sql query through dapper but when I do some profiling on this on every query that i perform to npg sql I see an extra ExecuteScalar query that is sent on that connection. And there are multiple NpgsqlConnection.Close events. I run the query in a using statement that terminates the NpgsqlConnection as follow.

        using (var connection = new NpgsqlConnection(connectionString))
        {
            return connection.QueryAsync<T>(sql, param);
        }

The but it also runs this extra command one every sql that i send through this code -

SET extra_float_digits = 3
SET ssl_renegotiation_limit = 0
SET lc_monetary = 'C'
SELECT 'Npgsql73113'

Here is the profiler screenshot of the relevant section. Any one know why there is this extra query and multiple Connection Close events.