70 years old and have a part time job that has made me $1700. Do I need to file taxes

Probably not.  If you have NO other income, and your social security is less than $48,000, you would not need to file a return.

If you do have other income, then it depends on how much other income including pensions and non taxable interest you have and if your total taxable income is higher than $16,650 if you are single. 

If your combined income is more than $25,000 or you are married filing separately then your social security becomes taxable up to 85%.

Your combined income is calculated by adding your

• AGI plus
• Nontaxable Interest plus
• 1/2 of your social security Benefits

If you fall into the following, 85% of your social security is taxable income

• Single with income above $34,000
• Married Filing Jointly with income above $44,000
• Married Filing Separate regardless of income

If you fall into the following, 50% of your social security is taxable income

• Single with combined income between $25,000-$34,000
• Married Filing Jointly with combined income between $32,000 and $44,000

Social Security Benefits Taxes