(a) The commissioners court of a county with a population of more than 100,000 that has a county hospital may acquire sites and construct or otherwise acquire buildings to use for county public health units or public health centers as part of the county hospital system. The commissioners court may locate a health unit or center anywhere in the county.
(b) Payments for the sites or buildings shall be made from the county permanent improvement fund. To pay for a site or building for a health unit or center, the commissioners court may:
(1) issue negotiable bonds and impose taxes to pay the principal of and interest on the bonds in accordance with Subtitles A and C, Title 9, Government Code;
(2) issue time warrants and impose taxes to pay the principal of and interest on the time warrants in accordance with Subchapter C, Chapter 262, Local Government Code; or
(3) by order issue certificates of indebtedness and impose taxes to pay the principal of and interest on the certificates in accordance with this section.

(c) The certificates of indebtedness must:
(1) mature not later than 35 years after the date of the certificates; and
(2) be signed by the county judge and attested by the county clerk, either by their actual or facsimile signatures as provided by the order of issuance.
(d) The interest on certificates of indebtedness may be evidenced by interest coupons at the discretion of the commissioners court. The interest coupons must be executed by the facsimile signatures of the county judge and county clerk.
(e) The certificates of indebtedness and the record relating to their issuance shall be submitted to the attorney general for examination. If the certificates are issued in accordance with the Texas Constitution and this section, the attorney general shall approve the certificates and the comptroller shall register the certificates. If the certificates are registered, they are incontestable after they are delivered to the purchasers.
(f) The commissioners court shall sell the certificates of indebtedness for not less than their par value plus accrued interest. The commissioners court shall impose a continuing annual ad valorem tax sufficient to pay the principal of and interest on the certificates as each becomes due and payable.
(g) Certificates of indebtedness issued under this section are negotiable instruments.
(h) The commissioners court may issue refunding bonds to refund bonds and certificates issued under this section, subject to state law applicable to refunding bonds issued by counties. The commissioners court may issue the refunding bonds without notice or a referendum.
(i) The commissioners court may issue refunding bonds to refund time warrants issued under this section.