reading multiple row lines from query in power shell.

I currently have a powershell script that returns one row of data, the script goes like this:

    $Query = "SELECT 
                 t1.BSM_NM
                ,t1.D_DTM AS MAXDATETIME
                ,CASE
                    WHEN SUM(t1.V_CUST_BLK_CNT)/SUM(t1.V_ATT_CNT) >= MAX(t2.MAJOR_VOICE_BLOCK) AND SUM(t1.V_CUST_BLK_CNT)/SUM(t1.V_ATT_CNT) < MAX(t2.CRITICAL_VOICE_BLOCK)
                         OR
                         SUM(t1.V_DRP_CALL_CNT)/SUM(t1.V_ATT_CNT) >= MAX(t2.MAJOR_VOICE_DROP) AND SUM(t1.V_DRP_CALL_CNT)/SUM(t1.V_ATT_CNT) < MAX(t2.CRITICAL_VOICE_DROP)
                         OR
                         SUM(t1.V_AXS_F_CNT)/SUM(t1.V_ATT_CNT) >= MAX(t2.MAJOR_VOICE_AXSFAIL) AND SUM(t1.V_AXS_F_CNT)/SUM(t1.V_ATT_CNT) < MAX(t2.CRITICAL_VOICE_AXSFAIL)
                    THEN 1
                    WHEN SUM(t1.V_CUST_BLK_CNT)/SUM(t1.V_ATT_CNT) >= MAX(t2.CRITICAL_VOICE_BLOCK)
                         OR
                         SUM(t1.V_DRP_CALL_CNT)/SUM(t1.V_ATT_CNT) >= MAX(t2.CRITICAL_VOICE_DROP)
                         OR
                         SUM(t1.V_AXS_F_CNT)/SUM(t1.V_ATT_CNT) >= MAX(t2.CRITICAL_VOICE_AXSFAIL)
                    THEN 2
                    ELSE 0
                 END MAJORCRITICAL
                FROM DMSN.DS3R_FH_1XRTT_BTS_LVL_KPI t1
                INNER JOIN
                ZDMSN.DS3R_1XRTT_TRIGGERS_THRESHOLD t2
                ON
                t1.BSM_NM = t2.BSC_NM
                WHERE t1.BSM_NM = 'ARL1' and t1.D_DTM = (SELECT MAX(D_DTM) FROM DS3R_FH_1XRTT_BTS_LVL_KPI WHERE BSM_NM = 'ARL1')
                GROUP BY
                t1.BSM_NM, t1.D_DTM"      

    $data_set = new-object system.data.dataset
    $adapter = new-object system.data.oracleclient.oracledataadapter ($Query, $Connection)
    [void] $adapter.Fill($data_set)
    $table = new-object system.data.datatable
    $table = $data_set.Tables[0]
    $bsmNM = $data_set.Tables[0].Rows[0].BSM_NM
    $maxDT = $data_set.Tables[0].Rows[0].MAXDATETIME
    $majorC = $data_set.Tables[0].Rows[0].MAJORCRITICAL  

        if ($majorC -eq "1" )

the above query would return results in one row like this:

now, lets say I change it so it returns between 2 and 10 rows of data, and if there is just a 1 in the MAJORCRITICAL column, to do something and if there is a 1 and a 2 in the MAJORCRITICAL column to do something else. The query would now return data as such

How can I set it to read through multiple row results in the query?